Ah, web forums. Wonderful. Liberating. Fountains of wisdom. Kindergarten. Give man a paint brush and man shall create great works of art and culture. Give man anonymity and man shall create a drawing of a truly epic penis.
Web forums are actually a great aid to beginners and veterans alike. Most people are very helpful and happy to give advice and opinions. The premier web forum for modular synths has to be www.muffwiggler.com (yes, I know). Trawling around there can easily eat away most of your afternoons if you let it. You can find discussions on everything from synth vanity shots to the inner workings of a particular filter implementation. Many builders of synth modules read and post there and you can even find support forums for some manufacturers hosted on the site.
Another site which can be useful is www.gearslutz.com. I don’t think I have to point out that this synth business is depressingly male-dominated, do I? You do find perhaps an above-average share of muppets at this site but as long as you stay away from topics that attract the tin-foil-hatted crowd — “is analogue better than digital,” or “which is most important, the preamp or the microphone” for example — you can get great help here as well.