Look no further, because this guide will tell you everything!
At the beginning of the game, the only SPECIAL attribute you need to have high is Intelligence. It must be a minimum and maximum of 8. So put it to 8!
Suggestion: Add 2 to random and 3 to INT, leaving the rest at 5. (I choose STR, because I like to scavenge things and I can maximise it to 10, ((works with PER aswell)))
By LVL 3 you should have INT on 10.
Once you get out the vault you will immediately hit LVL 2. Select 'Intense Training INT'.
Now drop every single item (except your best armor) on the ground outside the vault. You should have a WG of 15-20.
You will now get to Rivet City BEFORE hitting level 3. There are two ways. The easiest is to open your console (tilde key ~), type in 'tmm 1' and hit enter. Then open your map and fast travel to Rivet City. (Note: To remove this cheat simply exit Fallout 3 and load again at Rivet City, you should have only Vault 101 and Rivet City as a map marker. The second way is to get their by some mean of not levelling up. The INT bobblehead is in the 'Science Lab', on a table by a locker, and some fresh vegetables. Avoid speaking to Doctor Li or you would have skipped a quarter of the main quest. Exit Rivet City and go to Megaton. Also, once you hit LVL 4 get the 'Educated Perk'.
18 x 20 = 360
320 + 18 = 338
338 + (3 x 16 = 48) = 386. This is the amount of points you will be able to distribute between 13 skills until you hit LVL 20.
If you collect all bobbleheads you will get a +10 for each skill.
386 + 130 = 516.
Once you hit LVL 5 get the Comprehension perk. The skill books are by far the best bonus in the game, being able to earn you up to 50 points per skill (48 for barter)
516 + (600 + 48 = 648) = 1164
So to get the remaining 136 points there are many perks, as you will on need to use 3 for bonuses, you have 17 perks that can get you to perfect.
Daddy's Boy/Girl (LVL 2) +10
Gun Nut (LVL 2) + 10
Little Leaguer (LVL 2) +10
Thief (LVL 2) +10
Iron Fist (LVL 4) +5
Scoundrel (LVL 4) +10
Size Matters (LVL 8) +15
Silent Running (LVL 12) +10
Cyborg (LVL 14) +10
Tag (LVL 16) +15
If you take all of these and Size Matters + any other above +5 you can perfect you character, so plan ahead.
After this, you will still have 5 bonus perks to use aswell. (Note: Impartial Mediation isn't a permanant upgrade perk, so it is not recommended, and it does not make your skill higher in your Pip-Boy.
The only hard thing in this guide is getting to Rivet City before reaching LVL 3