Jacek Handke shared this fantastic article about getting started in DIY synths with us:
I wrote a tutorial on how to begin with synthesizer DIY depending on your skills (and money). It is more “possibilities in synth DIY” oriented than the usual “how to hold a soldering iron” – focusing more around how to find a “starting point” for your hobby. I think it will be useful for people who want to make a synth but don’t even have an idea of where to start.
He outlines some nice kits and gives a pretty solid foundation to get started. He even gives a few links to external resources to learn more.