Scrap Metal - You can get caps and experience points after repairing the leaky pipes in Megaton. She is available after you are sent to the Arlington Library by Moira Brown during the 'Wasteland Survival Guide' quest. Pre-War Books - They sell for 100 caps each to Scribe Yearling at Arlington Library. It'll help you save a lot of time if you hack every terminal in your sight. It is also important for you to hack every terminal you see in order to get the 'Data Miner' achievement which requires you to hack 50 terminals. Once you are at level 7, 13, 19, and 29 you should make a save right before you level up so you can go back and switch karma settings. You'll need to have good, bad, and neutral karma at level's 8, 14, 20, (and 30 if DLC is acquired).
When you first start this game, you should always try to get good karma as it is the hardest kind to get. It will tell you what you should do first, what items to pick up, and what quests that are missable. Okay so this thread is for people who are just starting Fallout 3.