Hi Karen,,
My advice to you is to research thoroughly and correspond with other authors who have published with Lulu. I haven't heard anything negative. A good website for writers is Writers's Beware.

http://www.sfwa.org/Beware/

I attended a self-publishing workshop where my friend was the guest speaker chronicling his self-publishing journey. He chose IUniverse for his novel and is quite pleased. He was telling us that each publisher has a strength, so be aware of what you are looking for. IUniverse has a strong editorial process. Authorhouse is strong in their marketing adn Ex-libris is good with east coast contacts and presence. Whatever you do, make sure your book is professionally edited, both developmental and copy edited. Do your research.