Here are some links to other interesting synthesizer sites:

A very good starting point for modular synthesizers: http://www.modularsynth.com

Moog - the best of them all: http://www.moogmusic.com

All the old Moogs: http://www.moogarchives.com

Synthesizers.com:

Korg MS + PS series: http://www.korganalogue.net

All about vintage synths at Vintage Synth Explorer: http://www.vintagesynth.com/

And if that is not enough, Kevin Lightner has some excellent info at Synthfool

Order music online:

Groove Unlimited

MusicZeit

The best step sequencer you can imagine

Artists of interest:

Atle Pakusch Gundersen

Erik Stormer

Tangerine Dream

Klaus Schulze

Jean-Michel Jarre

Modulator_ESP