Many skills, traits and perks are useless.
Sure you can just 'roleplay' instinctively but you'll be inadvertently penalizing yourself because you don't know the details of the game mechanics making the game harder.
Generally the three best skills are:
Small Guns (you'll be using them for a large part of the game, maybe half, and the beginning is the toughest - I don't think you'll find any useful Big Guns)
Speech - extremely useful in opening up a lot of extra dialog and quests
Lockpicks - many doors and locks to pick or you'll miss out on several locations. Most will have alternate ways of accessing them, electronics or science or something but lockpicks are the most common and generally the easiest - many checks work on 'threshold' values, so there's no random roll, if you have skill 79 and it requires 80 you won't be able to get in
Gambling and Outdoors and the Barter skill are relatively useless
For stats, a few stats work in a way that they give you benefits only on rounding down your score. So for example, Endurance 5 instead of 4 gives you zero extra hit points, but spending one more point to get 6 will get a very considerable bonus at medium/high levels when they add up. Agility is similar, any odd number gives you no extra Action Points. Many extra dialog options open up at a specific Intelligence value, which I think is 7
Also stat increases are very rare in the game. But some stats can be increased by two or three points if you made sure to get them. So it is sometimes worth taking an odd starting stat value or INT 7 knowing you will get a bonus later on (otherwise it will be 'wasted')
Google Per Jorner Fallout if you want more detail, he's got the most complete FAQ/Walkthrough, and has a very handy section at the beginning on Character Creation, so you don't need to see any spoilers.
Also make sure you get the latest patches, can't remember what it is but there's a very stable 'unofficial' patch at NMA-Fallout which is considered the standard
Have fun!
edit:
I personally like Luck based characters very much also. Take Luck 7 or 8 and the trait that gives you +10% to critical chance (you will start with 17% critical vs the 5% at default). Add a bunch of other perks, and it can be quite powerful.