I have built two guitars so far from kits. One based on the Fender telecaster,
the other was a bass also based on a Fender.
Both bought from Thomann musikhaus in Treppendorf, Germany. Very good kits, well constructed. The spaces for the controls & pickups required a little
smoothing off with a very light sand paper as did the main body to prep for staining. There are quiet a few items on youtube regarding the painting of guitars, however some can be a little confusing with regards to prepping & painting & what paint to use.
The instructions were in german, but was lucky enough to have a work colleague who speaks german & could get the English version of the internet.
Once one had been completed the other was a lot easier. The screws for the machine heads are quiet small, compared to those for the scratch plate, you could be forgiven for thinking it was the other way around. All parts needed to be checked off from the list provided.
I did find that the strings were not that good as I snapped one when tuning the Tele, therefore it would be better to have a good quality set to hand.