For Readers:
Abyss & Apex
Aeon Speculative Fiction
Apex Science Fiction and Horror Digest
The Internet Review of Science Fiction
Locus Online
Rogue Worlds
Sam's Dot Publishing
Strange Horizons
Tangent Online

For Writers:
Duotrope's Digest
Horror Writers Association
Ralan's SpecFic & Humor Webstravaganza
Science Fiction and Fantasy Writers of America
Science Fiction Poetry Association

Of Artistic Interest:
Interstitial Arts Foundation
Speculative Literature Foundation