I'd also like to get some feedback here. By the this time next year, I will have three full-lenght pieces floating around. I bypassed agent representation when I got picked up by my publisher. But getting an agent to "sell" me better might be a nice thing at this point. I'm selling in the hundreds; I would prefer the thousands.
I think you just find authors your work is similar too, then find who their agent is. Sometimes they give thanks to them in their books, sometimes mention it on the website, or googling the author can bring up the agent house who supports them.
As for finding an agent who you get along with on a personal level... well, I think that's pretty hard. I know a few authors who've changed agents after a few books, and there hasn't seemed to have been any 'I should have done this while picking' - it's just something you can't tell until you've worked with them, sadly.
I've only just started the query process, so I'm hardly the voice of experience, but I wholly recommend Query Tracker. It'll allow you to search agents by genre, see some of the clients represented... although those lists are user-edited, I think, and therefore not always accurate--you'll definitely want to double-check with the agents' sites. Also, it helps you keep track of who you've queried.
I'm librarylily over there, though I mostly just lurk and use the agent list.
I just sent out some letters to agents this morning and am hoping to gain representation through someone here in the UK, although I could only find information of 7 agencies that would consider fantasy writing. I thought this was a little on the limited side. I tried to get an agent a few years ago and never managed it, but I see from Map the Dragon's post it is possible to get a publisher without one. I self published my books and would like some help to get them out to the masses.