If you're into jazz learning resources, Bob Keller's Jazz Page is the motherload. Bob teaches computer science at my alma mater. He also plays trumpet and teaches a jazz improv class every semester. I took it six times.
Over the years of playing, learning, and teaching, he has compiled an enormous list of jazz resources on the web. Included are articles, books, musical calculators, music shops, discussion groups, lessons, musicians, music software, radio stations, venues, workshops. I love technology.
(He also included my Interval Trainer, written to help me identify interval spellings by note names.)