Query Tracker - Keep track of all the agents and publishers you've sent queries to. Updates and notes about each one are posted under their file.
Agent Query Connect - Need help writing a query letter? This group is ready to give suggestions and critique on that important first step.
Scribophile - Writing Community when you're ready for feedback.
CPSeek - Looking for Critique Partners? Look no further. Started by Brenda Drake (the awesome force behind many pitch contest such as Pitch Wars) this site brings together writers looking for others to exchange critiques with.
Preditors and Editors - Ready to query your baby? Got an offer from an agent? Before you sign that contract or hit the 'send' button on a query to every agent in existence, check out Preditors and Editors. Not only will it help you find an agent who's a good match, it also keeps tabs on which agents (and publishers) to avoid and which ones you can celebrate getting that deal from.
Writer Beware - Along the same lines as Preditors and Editors, Writer Beware includes posts and articles on warning signs and the latest scams to pop up in the writing world.
Absolute Write - Another site for advice and news on agents and publishers - both the good and bad.
Autocrit - Do you constantly get told you overuse certain words? Pacing is off? Too many cliches? Try running your work through Autocrit. There's a free trial or, if you like it and plan to use it constantly, different levels of membership.
Edit Minion - fledgling site similar to Autocrit, but without the memberships.
Pro Writing Aid - Another site set up to help with editing. This one is free.
Indie Store Finder - This is part of a larger website and Indie community, but this particular page is a huge help if you have to promote your own book. Type in your zipcode and it will pull up information for surrounding Independent Bookstores.
Jennifer Represents (Word counts for different genres) - this links to a particular post concerning what is industry standard for word counts. All of Jennifer's blog has helpful tidbits on it, so I encourage you to take a look.