what I've gathered from my contacts at bethesda and the legendary lady caffiene herself.
(if you ever worked for bethesda, obsidian, or any major game company, you SHOULD know who she is. if you don't, well, I honestly don't know what to say to ya. /\/008 XP
hand-to-hand will be similar to the other weapon skills, in that, the more you level the SKILL up, the more speed, accuracy, and power your unarmed attacks will have.
also, higher skill levels unlock new attack animations, making fighting more visually appealing. for instance, with H2H, you start out as a slow slugger, pugilizing anything stupid enough to piss you off. you then go on to gain faster, more skillful punches, then some elbow strikes, hand chops, and even a headbutt, till, towards the begginning of the middle of the skill, you get some knee strikes, then some full blown kicks, and finally, you get some "Bruce Lee Skills" as the guy's are calling em, jump kicks, flip kicks, backhands (gotta keep dat pimp hand STRONG!) sweep kicks, and believe it or not, a crotch shot.
you can level up H2H by fighting, or you can seek out the H2H masters around skyrim.
these warriors offer special training and with it, special feats to increase your abilities.
I only know of one H2H trainer: siegfried the iron fisted drunk, master of bar room brawling.
his techniques are basically the nord style of drunken boxing, allowing you to get tougher, stronger, and faster by getting drunker, and even healing by drinking nordic ale and mead.
there are 10 masters in all, scattered around skyrim, each with certain requirements to train with. siegfried's is that you get him some ale, a fine arsed wench, and a jar of honey.
when it comes to perks, the unarmed martial artist is going to have to specialize nearly their entire perk selection to H2H perks if they want to be the most bad assed son of a ***** in skyrim. but it seems that they'll be well taken care of for it.
the perks I've learned of seem to be divided into 4 categories: striking, grappling, defense, finishing moves. yes, you read that right, G-R-A-P-P-L-I-N-G!!!!!
striking: these perks involve striking the enemy in some way, usually with fists and feet.
weaponized body: basically, this feat multiplies your damage by your skill level.
think of your fist as being the same as any other weapon. but, while others can buy newer, better weapons, you only have what the nine gave you. this allows your fist to be on par with weapons, for instance, at level 1, your fists would be considered as iron weapons. at level 100, they would be considered as deadric weapons. this is a must for any martial artist.
Khajiiti paw of Pain: when using a foreward power attack, you can do a palm thrust, which causes the enemy to fall down and writhe in agony, leaving them wide open for attacks.
argonian tail smash: when using a backwards power attack, you do that kick will smiths son did at the end of "The Karate Kid" 2010, you know, the reverse somersault kick? you smash the enemies head, leaving them stunned and damaging their intelligence.
nordic dervish: when using a standing power attack, you unleash a series of spinning kicks, knocking all enemies around you away and to the ground. it's supposed to look really cool.
imperial sidekick: when using a left or right side power attack, you kick the enemy with all your force in their rib cage, sending them several feet in that direction, and knocking them down. this is supposed to be dificult to pull off, but highly useful.
falling dragon: when using a jumping power attack, you shoot through the air, and smash them in the head, just like everyones favorite porn stached plumber, Mario! XD
piercing strikes: your strikes now ignore 1 point of enemy armor rating for every 5
hand-to-hand skill levels you posess. so that's 20 points at level 100.
fatiguing strikes: your strikes now do double fatigue damage. rather useful.
grappling is focused on damaging the enemies stats 1st, their fatigue 2nd, and their health 3rd. basically, grapples are sneak attacks for unarmed characters. surprise the enemy, weaken them, and then ground and pound them to oblivion. and no, there will be NO hot oil wrestling.
also, it should be noted, grappling only works with roughly humanoid shaped and sized enemies,
so, no, you may not grapple with that dragon, thats what striking is for.
grappling feats are focused on increasing your ability to stay in the fight, as grappling is somewhat exhausting, and on increasing your ability to enfeeble the enemy.
rough and tumble: this feat gives a bonus to natural armor rating, health, fatigue, and reduces the fatigue and health costs for grappling. it's a bonus everyone should get.
down and dirty: further enhances natural armor, health, and fatigue, further reduces grappling fatigue and health costs, and increases the chance to inflict debuffs on the enemy and increases the duration of the debuffs. again, usefull for everyone.
godhand grappler: a final bonus to natural armor, fatigue, and health, a final reduction to health and fatigue costs, and doubles the chance of inflicting debuffs from grapples and their duration. this basically makes you fit as fuck, so there's no reason not to get it.
arm breaker: when sneak attacking an enemy from behind with a left or right power attack, you attempt to break their arm, disarming them, and damaging their strength.
neck breaker: when sneak attacking an enemy from behind, and using a forward power attack, you attempt to break the enemies neck, killing them instantly. damned difficult to pull off.
Nordic Suplex: when sneak attacking the enemy from behind with a standing power attack, you pick the enemy up and slam them headfirst into the earth, stunning them and damaging intelligence, willpower, and personality. this is basically a mage killer.
imperial catapult: when sneak attacking an enemy from behind and using a backwards power attack, you grabthe enemy, fall to the ground, and use your legs to launch them into the air, falling in a heap over a dozen feet away from you, damaging all of their stats to a moderate amount. this one is probably the least powerful, but most tactical of the grapples.
defence perks focus on giving a martial artist the staying power he needs to survive.
they enhance natural armor rating, health, fatigue, resistances, and blocking efficiency.
their useful to any martial artist, but especially to those who don't want to use armor.
Armorized body: this feat allows you to increase your natural armor class by raising certain skills, such as H2H, mobility, and block. you start out normal, but when maxed out, your natural armor rating is as good as the best armor in the game.also, this let's your unarmed, unarmored blocks be just as effective as using a shield and armor. hate armor? get this.
unyielding mountain: increases natural armor class, health, fatigue, resistances, and makes you immune to being knocked down. all good things for everyone.
unending river: increases natural armor class, health, fatigue, resistances, and makes you immune to strength & fatigue stat damage, though you can still lose fatigue by taking damage.
limitless fire: increases natural armor class, health, fatigue, resistances, and makes you immune to endurance & health stat damage, though you can still lose health by taking damage.
ceaseless wind: increases natural armor class, health, fatigue, resistances, and makes you immune to being paralyzed, stunned, or recieving speed or agility stat damage.
infinite void: increases natural armor class, health, fatigue, resistances, and makes you immune to being intelligence, will power, personality, or luck stat damaged.
finisher perks grant the ability to use special finishing moves upon opponents in special situations, often to devastating effect. unarmed gets striking and grappling finishers.
striking finishers:
the masters one inch punch: stun an enemy, then unleash the legendary 1 inch punch, dealing massive health, fatigue, and stat damage, and sending the enemy flying. costs fatigue.
soaring dragon: basically, this is a shoryuken with quite a bit of range. you bursts forward at a flying or falling enemy, and unleash a massive rising uppercut while surrounded by ripping, galeforce winds. the enemy must be airborn to use this. costs fatigue.
swooping dragon: basically, this is a flying, horizontal kick at a charging enemy, dealing massive damage, and knocking them vary far away. it can be hard to pull off. costs fatigue.
fists of oblivion: strike a paralyzed or fatigued enemy so hard they explode. costs fatigue.
grappling finishers:
Pillory: you sneak up on a guy, jump above him, and snap his neck whilst in the air above him. ninja seem to prefer using this same attack in the way of the samurai games. the target cannot be aware of your presence. costs fatigue. very hard to pull off, but 100% kill chance.
Werebearhug: grapple an enemy with at least one broken arm, and crush them to death, like what happened to that jacob fellow at the end of eclipse, but worse. costs a lot of fatigue.
(on a side note, those who want to be were's will not be dissappointed by this game!)
ice wraith constriction: the mother of all grapples, take a paralyzed enemy, and break every last got damned bone in his entire frieking body. this is awesome to behold. costs fatigue.
and there you have it folks, hand-to-hand in skyrim, as far as I've been able to learn.