Building computers is much easier and quite a bit safer than you think - if you can put together a LEGO kit, then you can put together a computer just as easily
Every part comes with instructions on how to fit them into each other (for example, the RAM will have instructions on how to fit it into the motherboard - and the motherboard manual will too).
Computer parts are pretty durable, and can usually withstand you dropping them (not that I recommend you do). Try not to touch the parts (with your hands) where they connect to each other - though even if you touch them accidentally you're unlikely to run into any problems.
If you're sure you don't want to built it yourself, then we can help you choose parts. You can probably find a computer shop who will be happy to put the parts together for you (for a price, obviously). Try looking in the Yellow Pages, assuming where you live has one.