Right well I'm no pro, but as this is a DIY site I'll give my penn'orth.
First and foremost a couple of drills, one variable speed cordless, one SDS plus. Don't need to be expensive.
Second. Decent drill / screwdriver bits. Don't bother with the sets of drill bits, you are most likely to need 5 - 8mm drills. Doubt you'll ever use 1-4 mm bits
Trade pack of screws, cheap and you won't have to constantly searching for screws.
Couple of saws, S&J Predators will be fine. You don't need a circular saw, and you definitely don't need a Jigsaw, which is probably the most inaccruate tool in a DIY'ers tool box. The really expensive ones are OK, but the cheap one's are s**t. Maybe a hacksaw as well.
Stanly knife, with lots of spare blades, don't dick around with blunt blades, you will cut yourself if you do.
Pliers, Combination ones are fine. You don't need wire strippers, use the stanley knife.
That's about it really, the vast majority of DIY activity is putting a hole in something, and connecting 2 things together.
Oh, set of handheld scredrivers as well Wera ones are excellent in my opinion.
