I learned by far the most I Have learned from the Tom Rhea authored MicroMoog manual. He worked with Bob (developed the Crumar Spirit with him as well as many other things in is own right), was a physicist and engineer and his manuals are such that everytime you pick them up you will learn something.
The nomenclature of Analog Synthesis is so voluminous that approaching the subject from a beginners standpoint (like me) with little to no knowledge of the fundamentals of electronics (like me) can be extremely intimidating and makes for a high learning curve. Once you become familliar with the terminilogy, everything else comes with lots of time, and many hours on the toilet with the manuals.
THe Tom Rhea MicroMoog manuals (as well as other resources) can be found here.
http://www.fantasyjackpalance.com/fjp/s ... omoog.html
I would start with the MicroMoog manual, maybe see if you can find a minimoog manual by Rhea as well. Then of corse all of the current Moog Music Manuals can be found on their respective product pages, and those (specifically the cp251, the Ring Mod) will provide lots of supplimental information. Be sure to read the Voyager manual too.
Then, After you paruse the MicroMoog manual, head on over to moogarchives.com, click on Instruments, then Modules, and then on the right you will see a list of most of the Modules that Moog offered. When you pick a module, it will give you a functional description and a Musical Application of each module, which will definately give you some ideas. Not only that you will love checking out their site if you haven't spent hours oogling the vintage synth porn that is there.
Then, if you still want some information, feel free to ask questions here as there are individuals here that are engineers and musicians and have spent countless hours helping me and other people learn about the Principles of Analogue Subtractive Synthesis.
Theres also the Analog Cookbook, which is a recipe book for sculpting sounds. It shows which waveshapes are best to use for which sounds. You can find it here
http://www.synthesizer-cookbook.com/
Im sure that there are other resources like other companies instructional manuals and other online resources that people can give you that I can't think of, but Id start there and thats enough to last you for years.
Good luck!
Eric