Inkspot
http://www.inkspot.com?
The Market List
http://www.marketlist.com/
Professional Markets List
This is a resources list that is geared toward SF/F/H writers but it has a lot of links to articles that would benefit writers in general.
http://www.forwriters.com/references.html
SF/F Magazines
http://www.sfwa.org/links/mags.htm
Writer's Guidelines Data Base
http://mav.net/guidelines/index.html
The Writer's Place
Whoa! Check this out! A searchable database for all genre
http://www.awoc.com/Guidelines.cfm
Writer's Write
http://www.writerswrite.com/paying/
Century's Recommended Publishers
http://www.supranet.com/century/links.html
The Write Markets Report
http://www.writersmarkets.com/index-links.htm
Web page of Pro Markets
Mostly fantasy and sf markets.
http://www.cs.cmu.edu/~mslee/mag.html#prof