Hi Blizabeth, and welcome to the chronicles network - sorry about delinking, but we get an awful lot of aspiring writers who join up simply to try and promo their book, so it's something that generally applies, not just to you.
As for asking about agents - I have to admit to being a little surprised that you have the time to pay for publishing via Authorhouse, but haven't even begun to think about agents and traditional publishing until after. In which case, I think you'll find you'll need to prove your worth via your book sales, as you have already become a published author in one sense.
As for lists of agents - which country are you in? There are different lists for the UK and USA and I can't tell which one you're in from the information above.
Anyone after information on UK agents in SFF may find this list useful:
http://www.chronicles-network.net/wr.../agents/uk.php
However, I'm afraid I don;t have a comparable list of US agents.
Hope that helps for starters.