I'll ease you into the week slowly by sharing a tip that's as short and simple as it gets. As you play through Fallout 3, you'll notice that some of the environments are pretty dark. Although the darkness might best complement the game's bleak and sinister tone, it often makes things more difficult for you.
There's some serious gratification to be had by sneaking up on a baddie and getting that critical strike damage. If you're finding that super mutants always seem to see you before you see them, you can change the darkness settings to lighten things up a bit. Just hit the start button from your game and choose "settings" and from there find "display." In the display options you should be able to adjust the brightness. This helps you see what's across the room, giving you the chance to gauge the situation before the situation runs in on you with bullets flying and sledgehammers swishing. If you want to get the first shot more often, consider lightening up your settings.