In order to know where to allocate level-up points, you need to know what skill levels will be needed.
The list below shows those requirements for places you will visit as you play FONV.
Of course you can be short up to 20 points if you have a magazine to make up the difference.

Skill points you see in the morning are reduced in the afternoon and even more at night, but this should only be a problem in Vault 34 where the constant radiation keeps you from Waiting for 6 a.m.

GoodSprings: Repair 25, Science 25, Lock 25 (school safe), Lock 50 (safe), Explosive 25
                         Medical 30 to get more meds but no XP.

Lonesome Road: Lockpick 75 (optional), Science 35 to get XP from ED-E.

Primm: Lockpick 75, Repair 30 + Magazine, Speech 40, Science 50. Elevator: Repair 35 but no XP.

Jean’s Sky Diving: hard lock but a key is provided.

Sloan: Medical 30 for Snuffles, Repair 35 for generator

Nipton: Repair 35 (not worth it), Lock 75 (but a key is provided)

Novac: Speech 40 for Boone (or 38 with jumpsuit or 35 with buisnessware)

Ranger Station Charlie: Repair 45 (not worth a mag nor raising Repair above 30.)

Repconn: Speech 50, Science 55

Boulder: Speech 45

Vault 3: 75 Lockpick

Vault 34: 100 Lockpick : 20 mag + 80 Lockpick, but probably at night, so need more than 80 without EB+FE.

Building with Sniper rifle, ENE of Med Center: 75 Lockpick, optional: mines and trip wire.

Winn’s Hideout: Speech 55 (optional)

McCarran: Speech 60 or Med.40 (Betsy). Speech 40 for Hildren.

Freeside: Programming 75 (for FISTO), Speech 60 (The King), Lockpick 75 (Graf)

Strip: Medical 55 (photo mission)

Vault 22: (Optional) Repair 50 for elevator. Lockpick 75 for elevator to 5th level.