mikozero said:
if you are really, really stuck to the point you aren't enjoying the game type "fallout wiki" into google
This my friend is sound advice!
http://fallout.wikia.com/wiki/Portal:Fallout_3
I pretty much play with this open in my laptop beside me every time i play this game, its so useful to just read up on everything and making sure you don't miss things or find stuff you wouldn't of otherwise found and i find it really interesting to read about the alternative paths and consequences that would of happened if you took a different approach. Although read with caution so as not to spoil anything for yourself!
My advice would be crank up your repair skill, stick with mainly small guns for now but slowly level up big guns and energy weapons as they will be useful later in the game. And just loot everything you can carry, go into every building, search everything, hack and lock pick everything (unless it means losing karma) and just explore the areas of the waste around where your next objective is before you start the next quest and you will have a ton of caps and good guns and a better character for it. Take you're time! The main quest isn't all that long so don't just rush through all the main missions get the most out of the game by just exploring the wastes and finding every side quest.
Also here's another piece advice that someone gave to me when i started out,collect the nuka cola quamtums don't drink them cos theres a quest involving having 30 of them and theres only like 98 or something in the whole game (unless you have broken steel)I can imagine it would be a real ***** if you've gone around drinking them the whole time so just collect them and give them to you're companion or store them somewhere or something and then that's an easy side quest/achievement to get when it could of been a real *****!
Anyways good luck!!