Here's a blog with loads of terrific posts from writers, agents and industry professionals - http://writerunboxed.com/
Karen A. Fox has been a longtime favorite site of mine. She lists romance agents and publishers - http://www.karenafox.com/publishers.htm
Here's a list of keyboard shortcuts that has come in handy for me more than a few times - http://www.nouilles.info/keyboard_shortcuts.html
Author Kristen Lamb has a very informative blog about writing and promotion that's always worth a read - http://warriorwriters.wordpress.com/
Our very own Jax Cassidy is co-founder of this site, which is chock full of great info, from online classes to forums full of helpful tidbits from authors - http://romancedivas.com/
Last, here's a post that catalogs many review sites that get awesome traffic - http://kathleendienne.com/review-sites-roundup/
This should get you started. Do you have any go-to sites you'd like to share?