Rock
Annual

History—archives and discographies:

Archive of Contemporary Music

Audio Culture

Beatles Bible

Billboard Top 100 Songs of Every Year

Blissblog
Simon Reynolds; not updated much, but the place to go for links and more about his books

Blues Hall of Fame

Center for Popular Music

Chicago Punk Database

Dave's Music Database

Discography of American Historical Recordings

Bob Dylan

Fall Online

First Sounds

Ted Gioia

Marv Goldberg's Yesterday's Memories Rhythm and Blues Party

Gonightclubbing Archive

History of Rock 'n' Roll: The Golden Decade 1954-1963

Tom Hull

Independent Voices
Complete scans of the Ann Arbor Sun, the Berkeley Barb, the East Village Other, the Los Angeles Free Press, many more

Information Is Not Knowledge

Inner City Sound

International Times Archive

Paul McCartney Project

Mr. Blint's Attic

Monkees Sessionography

Motown Junkies

Old Time Blues

Prince Vault

Residents Official Site

Rockabilly Hall of Fame

Rocklist

Rock's Backpages
Subscription library of writings by music critics; free articles

Red Saunders Research Foundation
Features numerous discographies, not least of the Aristocrat and Chess labels

Soulful Kinda Music
A magazine too

Southern Garage Bands

Spontaneous Lunacy: The History of Rock 'n' Roll - Song by Song

Synth Museum

Tinfoil

Trouser Press
Occasional new writings, but mostly full-text scans of every issue of the magazine

Tunecaster

Richie Unterberger

Vocal Group Hall of Fame

Wirz' American Music

Neil Young Archives

Zappa Books


Periodicals and radio-television programs/ stations:

Big Takeover

Blues and Rhythm

Dangerous Minds

Definitive 1000 Songs of All Time 1955 to 2005
Defunct; incomplete

Fast 'n' Bulbous

Goldmine

Joop's Musical Flowers

KFJC (89.7 F M, Los Altos, California)

Lefsetz Letter

Luna Kafé

Mark's Record Reviews
"Retired"

Music Aficionado

My Back Pages

Perfect Sound Forever

Please Kill Me Online

Pop Chronicles

Quietus

Rubber City Review

Scram Magazine

Synapse
Internet Archive-d

Tape Op

Ugly Things Magazine

Under the Radar

Wire

Wax Poetics

WFMU (91.1 F M, East Orange, New Jersey)

WKCR (89.9 F M, New York, New York)

WREK (91.1 F M, Atlanta, Georgia)

WWOZ (90.7 F M, New Orleans, Louisiana)


Further afield:

Discogs

45 Worlds

Steve Hoffman Music Forums

Rate Your Music