software:
www.audacity.sourceforge.net (audio editor)
www.gimp.org (graphic editor)
www.lame.sourceforge.net (mp3 encoder, --> windows interface)
www.mp3tag.de/download.html (mp3 tag editor)
www.rebirthmuseum.com (digital TB-303 simulator)
www.sourceforge.net (gigantic open source software ressource)
www.toolsandmore.de (many useful tools for windows)
www.ubuntu.com (linux, easy for beginners)
www.videolan.org/vlc (media player)