I'll throw my hat in the ring to defend Essentials; If you have never run a D&D campaign before, it's dead easy.
BooksJust get a Dungeon Master's guide for yourself, and for the players a book called Heroes of the Fallen Lands; it has several races (off the top of my head, I remember human, elf, dwarf, halfling, and eladrin) and the classic character types (fighter, mage, rouge, cleric), along with an easy-to-follow character creation bit (including player sheets) and an explanation of the major rules. Basically, with those two books and a couple hours you can create a party of adventurers and get the players to know the basic mechanics of the game. (if you have more people, or they want to make things like druids, paladins and dark elves, pick up the companion book Heroes of the Forgotten Kingdoms).
There is a treasure handbook of a kind in Mordenkainen's Magnificent Emporium, which is full of magical gear, but you don't need it right away; the DMG has some magical items in it, along with tables for calculating gold. Ditto for the Monster Manual; get a module with some prebalanced encounters (fights) to give you an idea of what to throw at a party.
Dice: Pick up a prepackaged tin, ask the guy at the hobby store for a basic set. You need seven dice types: d4, d6, d8, d10, d12, d20 (that is, a 4-sided dice, a 6-sided dice, etc.) This should only set you back a couple dollars, but encourage your players to get their own sets; it's a real pain to keep handing around the same few dice.
Module Like McMindflayer said, a module (prepackaged adventure, complete with monster stats, NPCs and maps) is your best bet for out-of-the-box gaming. Trust me when I say that you do not want to have to create your own world and adventure on your first run; you'll get caught up in dumb details and end up with some half-baked nonsense. Run a module or two to get an understanding of what it is to be a DM, then decide if with your group if you enjoy that setting, want to try a different one, make up your own, or even have someone else run the games while you play. Graph paper can't hurt, but if you have the funds see if you can get an dry-erase map similar to the one Windcaler recommends; your maps should cover everything in the module, but adventurers are known to go off-book.
The Druid: This is a little tricky. If you are not going to be running the game, pass this info along the person who will and go nuts. If you are, I regret to inform you that D&D can't support you as both player and DM, unless you guys want to pass around gamemaster duties; it's no fun having your omniscient buddy tagging along.