here's some tutorial and discussion sites:
http://www.dogsonacid.com/forumdisplay.php?forumid=4
http://studioheadz.com/forum/
http://www.funk-station.co.uk/tutorials.htm

and here's a program that lets people that don't know how to create their own synths ... well, create their own synths:
http://www.synthedit.com/

you will probably find the most useful info at the first two sites above. cheers.

The music-dsp mailing list, and the related MusicDSP.com site, is for the hard-core.

I stand corrected.

You can get a TON of help from the Reason forums at http://www.propellerheads.se if you're registered.

In my experience, the most important thing when building up a synth sound is to have some idea what you want it to sound like. Just messing around with no direction sometimes yields interesting results but is more often than not tedious and unproductive.

Once you have a sound in mind, consider its ADSR characteristics. That's Attack, Decay, Sustain, Release, and on the Subtractor the main ADSR envelope is located near the middle (there's also one for the filter and one for the LFO I believe, don't worry about those for the moment).

Attack is how long it takes the sound to go from silence to full volume. Slow strings and pads have a slow attack while punchy piano stabs would have a quick attack. Move the slider up to slow the attack.

Decay is how much time it takes the sound to go from full volume to the Sustain level, after completing the Attack phase.

Sustain is the volume at which the sound will continue to play as the note is held. I don't usually use the Decay/Sustain sliders much but they can be useful for certain sounds, like if you want a really sudden, "stabby" sound that falls off into something more padlike... I don't know, I'm pulling this example out of nowhere. ;)

Release is how long it takes the sound to fade out to silence after the note is released.

Once you've got the ADSR envelope set up to emulate the sound you're making, then you can tweak the waveforms. Again, consider the final sound you want. There are four basic waveforms: sine, saw, square, and triangle.

Sine waves work well for woodwind-type sounds. Saw waves are excellent for brass instruments (and of course trance leads!) Square waves have a very old-school electronic quality - think Super Mario Bros. here, and triangles are, well... ok, I don't really use triangles, but they're like a brighter square wave I guess. :P

The Subtractor has like 30 other waveforms that are just numbered so you'll just have to experiment with those. Once the waveforms are adjusted to your liking, you should be getting pretty close to the sound you want. Now you can mess with modulation, noise, etc. Maybe use the LFO to add a rhythmic punch to the sound, or filters for minor adjustments. But the ADSR envelope and waveforms are the two key things in sythesis.

I am not a professional, this is just what I've learned from about eight months working with Reason. I've produced a few tracks at http://www.third-helix.com/mr_music.html if you want an idea of how my approach works (this is of course a shameless plug!)

Good luck! If you drop by the Reason forums, I'm known there as Mad Rabbit.

That is all.

Triangle wave is much softer and more mellow than a square wave, btw. Triangle has fewer harmonics and is more like sine.

Hi. I learned by reading the manual for my synth. I have a virus b, and the manual that comes with it is really useful for learning how to program a synth. There is an introductory section that assumes you know nothing. Although it assumes you have a virus, a lot of the parameters are common and will be on almost any other (substractive synthesis) synth.

http://www.access-music.de/downloads.php4?product=virusb#cat4

At the very bottom is a link to the virus b manual in english.

-j

If you're a coder, you might be interested in tools like Csound or SuperCollider, although the latter is only available for Linux and OS X. Both have quite active communities, though, and are very versatile synthesis languages. Csound also has an excellent accompanying book, which would be very worthwhile if you're interested in that language. Anyway, you might want to check those out.