Just a compilation of suggested links, which I'll add to as time goes on:
http://bookendslitagency.blogspot.com/ BookEnds Literary Agency Blog - the writer had a lot of very helpful articles on everything from writing queries to what to expect when you're publishing.
http://queryshark.blogspot.com/ QueryShark - if you're working on writing your query, READ THIS. It made all the difference for me. While she's harsh, the author is good, and being able to see her feedback on other people's work means you won't have to swallow the same kind of feedback on your own. Assuming, that is, you follow her advice.
http://www.rwa.org/ Romance Writers of America - Join, and you'll have access to their lists of romance agents, articles, writing contests, local chapters, and much more. Great networking tool, and if you intend to be a professional writer, you should join a professional writing association.
http://www.heartofcarolina.org/ Heart of Carolina Romance Writers - The local chapter of the RWA for me. Actually sitting down with published writers and talking to them? I can't stress enough how much that helped me. Really. I learned as much during a tea and dinner as I learned in three weeks of research, and most of it was entirely informal. Of course, if you're not a romance writer, you oughtn't join, but I'd suggest finding the equivalent of your genre. Not in North Carolina? The chapter does make exceptions for writers who live in states without a local chapter. Of course, I'd probably suggest going for the closest state and asking them if you can join. That way, you'll have a chance of being able to attend in person a little more often (theoretically, anyway. I know - it's hard making the time to go to meetings! But try. Trust me on this.)
http://www.ncwriters.org/ NC Writers - Where will you find your genre-equivalent of HCRW? Check here (or your state's writing network). What's the benefit of writing conferences? Getting to meet an agent in person, talking to other writers, general networking, and taking seminars that will prepare you for the next step.
http://virginiakantra.com/Links.html Virginia Kantra's website - she's been highly recommended to me by all of the members of HCRW as having excellent articles about writing, and those that I've read so far have been helpful.