links out of here:

• General music production:
• kvr the best VST, AU and DX instruments site
• MIDIplugins MFX, VST and OPT MIDI plugins
• sound on sound professional recording advice
• computer music / music radar hardware and software magazine for music makers & music producers
• gearslutz a pro recording website
• prosoundweb another pro recording site
• harmony central music equipment news site

• VST, AU, DX and OPT development:
• VST source code archive examples you might need to start programming your own plugins
• steinberg VST plugin development official home of the VST SDK and VSTGUI
• DX and MFX plugin development official home
• AU plugin development audiounits
• music DSP what you might need to put in your plugins