How was your experience with Smashwords? I've encouraged my daughter to publish her book there (it was an ABC book she did for a project in school but it whimsical, funny, educational and has great images she created for it).
It was not too bad but I do have a few thoughts. First, their style guide says that books with a lot of images don't work well as e-books so I don't know how her book would translate into an e-book if it has lots of images unfortunately. I really kept mine to a major minimum but the one image I put in, although it followed their formatting guidelines (jpeg, etc.) seems to have created an issue where it says that it didn't format perfectly and won't be acceptable to Apple as a result. They have a huge long fix it article on how to go about fixing problems of that sort, but I haven't had time to dig through it yet. I'm really not a programmer!
It doesn't look bad from what I could see when I looked @ the sample chapters, but apparently Apple can be pretty specific. They do have people you can pay to fix formatting errors but I don't know if I am going to make any money on this yet, so I'm not sure if I am going to invest in a format expert as of yet!