Authonomy Receive and give critiques, and possibly earn a HarperCollins review.

Writers Online Workshops learn craft and get/give critiques. 

Critters excellent science fiction/fantasy/horror critique group.

All Writers learn craft, get/give critiques.

Query Shark literary agent Janet Reid of Fine Print Literary Management critiques query letters.

BookEnds, LLC agent critiques query letters.

Nathan Bransford helpful advice and examples.

Agent Query tons of helpful info on writing a query letter and finding an agent/publisher.

Query Tracker find agents and keep track of your queries online.

Author sites and blogs

Cheri Lasota  Author of Airtimes Rising

Mo Poppet Writer of erotica, romance, horror, thriller 

Susanne O'Leary  

Toby Neal 

Chantal Boudreau     Writer/illustrator of fantasy, dark fantasy and horror. 

Ask the Experts an essential site for research. Ask an expert in just about any field questions

Writer's Digest information on all aspects of writing and publishing. Now has a free place for writers to post work for critique.

The Association of Authors' Representative (AAR) in short, the AAR holds member agents to a high standard of conduct. Search for agents through their web site.

Preditors and Editors Tons of good info, including a list of agents/publishers and a heads up on which ones are scammers.

The Writer's Site gateway to helpful sites.

TV Tropes data base of common tropes and cliches found in media. Helps with spotting cliches and learning how to set yourself apart.