Since the idea of the exercise is so the OP's son can learn about the inner workings of a pc, I'm going to have to disagree there.slo said:My general advice is to pick parts manually and then have someone in the store assemble it for you.
Partly because having someone else assemble it would more or less defeat the purpose, partly because building a pc is nowhere near as complicated as it appears at first glance if you do some research and prep work. I'm not technically inclined at all, but I was able to build, with no prior experience, a gaming pc in an afternoon, with only one slip-up[footnote]Finished building and tried to boot it. Nope. Turned out I forgot to run a power cable to the CPU. Whoops, such a brainless oversight.[/footnote]. It actually surprised me how quickly it went. Between the included manuals and the abundance of online guides on building a pc, there is little stopping someone from doing it themselves so long as they can read and use a screwdriver.
And besides being a rewarding experience, going hands on yourself is so much more educational. I learned more about pcs in that one afternoon than I did in the 20 previous years of buying pre-builts or picking parts and having someone else put them together.