Writerly Sites I Enjoy
Guide to Literary Agents : Just what the name suggests. Be sure to check out the Editor's Blog. They post new agent interviews and queries that worked. Every one will find something useful there.
Write-Brained Network : A forum for writers to meet and chat. You can find beta readers, critique partners, ask for help or suggestions or just commiserate with other writers.
Writer's Digest : Great tips, great magazine, great prompts and fun contests. My current WIP began from a short story writing prompt on their site. They also have a forum for discussions.
Writing Out of Order: A great blog post on overcoming writing slumps from the Veronica Roth, author of Divergent.
Query Shark : The Shark AKA Agent Janet Reid, slices and dices queries from aspiring authors much to their benefit and yours. You can submit your queries for critique, but be certain to read all the blog posts first. The Shark does not like to repeat herself.
Query Tracker : A helpful tool for keeping track of queries, agents, and discussing the process with other writers in the same stage of the game.
Bookends LLC Workshop Wednesday : The blog is no longer updated, but for a while every Wednesday a query was critiqued. Not as biting as Query Shark, but as useful, especially if you might query an agent at Bookends LLC. Just scroll through the common tags on the right and click queries to read through the results.
Fiction Writer's Connection
Guide to Literary Agents
From the Write Angle