weaklings... here is my guide:
First Aid: no points, just read skill books. The skill IS usefull, each use gives 25xp (that's 75xp/day if really injured) and saves stimpacks. That may not be anything late game, since the XP is low and stims are abundant, but in the begining it's a must.
Doctor: everything said above, except there are no book so go for 55 points when playing normal, and switch to easy when dealing with NPC's (75 is the highest check, in Vault City). Vault City training will increase it by 5 and Living Anatomy (very good perk) will boost further by 10, to a total of 70 on normal (90 on easy).
Seriously, 3 uses/day of each = 225 xp, that's very nice until around level 10, since it's free and easy XP.
Never say no to XP.