The new software Syntorial teaches you step by step how to program a synthesizer. It allows you to program the patches by ear. The idea is to create the exact sounds you have going on in your head. Synthorial is introduced in the video below:
Synthorial costs $ 100, but you can also find free information about programming synthesizers on the Internet. A few years ago I have learned a lot from the 17-part course Thor Demystified by Gordon Reid. It is still available on the website of Propellerhead Software.
This course shows the full potential of Thor, the great synthesizer which is part of Reason. In addition to a clear explanation of Thor, Gordon Reid also provides an excellent introduction to programming synthesizers in general. Reid discusses several synthesis variants. These are not only the subtractive variant, but also FM- and wavetable synthesis.
A license for Reason is not necessarily needed to follow this course. You can also use the demo of Reason 7, which is installed by default after full installation of the package. Possibly, you can even save Thor patches and open them again, but I’m not sure. If you have an iPad, you can also use the app Thor, which Propellerhead released a while ago.
Another option for learning programming your own synth patches is The secrets of subtractive synthesis “The 4 Element Synth”. This is a recent course on subtractive synthesis by the Dutch synthesizer developer Rob Papen, see also this promo video: