Many compositionists have already compiled lists of useful links pages. Below you will find some excellent examples:

AASU LLP's Faculty Resource Links

AASU LLP's Teaching Resource Links Page

AASU LLP's Instructor Support Links Page

Bedford Bibliography for Teachers of Writing

College of Dupage Composition Links

Dick Nordquist's Resource Page

Kairos Weblinks

Miami University's Center for Writing Excellence Online Reference Shelf

MLA

Irvin Peckham's Links Page at LSU

Professional Resources from Illinois State

Purdue's Online Writing Lab

Ohio State University Links and Resources

Rebecca Moore Howard's Bibliographies

THE Composition and Rhetoric Website: with extensive links

The Rhetoric Page at Kettering

Victor Vitanza's Webpage