i've also noticed that explosives aren't that good, since you can't even use them except in VATS..
Why do you say that? I use explosives all the time (mines + dynamite mostly) and have never used them in VATS. Explosives are awesome. After I realized that I chose it as my 4th tag skill and raised it up to 70.
Anyway, keep in mind you can buy an extra point in each SPECIAL area when you have enough of caps. Also keep in mind that Intelligence grants you extra skill points the higher it is so it is best to put more points into that as early as possible if that's important to you (some people start their character with 10 Intelligence, though I wouldn't go that far). Also keep in mind that one of the perks is double the temporary skill point increase from magazines so you might want to take that one early and put 20 points less into certain skills. That is, if you want to pick some average locks you can do it with 30 pts in lockpicking plus a 20 point increase from a lockpick magazine, so you wouldn't necessarily want more than 30 points in lockpicking. There is also a perk that gives you a permanent 4 point increase for reading skill books rather than the usual 3 points. Either take that perk early or don't read the skill books until after you have the perk.
So for my build the things I wish I had known about and done are:
1. Put more points into Intelligence at the beginning
2. Save all my skill books until I have the extra point perk
3. Save all my skill magazines until after I take the point doubling perk
4. Put 22 points into lockpicking at the beginning but plan on finding at least two Tumblers Today skill books to raise it to 30 as soon as possible. Then rely on lockpicking magaines to temporarily raise it to 50 when I need to.
5. Ditto Speech. Meeting People is much easier to find than the lockpicking magazine, whatever it's called.
6. Ditto Repair. Start with 22 points, find a couple of skill books to raise it to 30, then use Fixin Things to bring it up to 50 only when using a workbench at which point you can create Weapon Repair Kits.
So for me 22 is the magic number but that assumes I'll go after some skill books very early on.