I'm using CreateSpace to self-publish my soon-to-be-released book, "Here Be Monsters". While the editing is still in process, I cannot get too far into the guts of their online machinery, but have been very impressed so far.
They have extensive articles and forums for help and information, as well as live people at the other end of email addresses and phone numbers who respond to pleas for help within minutes (in the case of my phone query) or hours (in the case of my email query). Their online apps for planning covers and trim-sizes and book costs are instructive and easy to use.
They do offer assistance-for-pay for every step of the publishing process, but also allow those of us who want to go it alone to do so (with help from the exhaustive resources available to members). The option that I'll be paying for in the whole process will be expanded distribution ($25), which makes my book available through other bookstores beside Amazon.com and libraries and other academic institutions and other resellers (through B&T and Ingram and CreateSpace Direct).
I was surprised today to find that my 180 page manuscript translated into 360 pages, when dropped into a pre-made template CreateSpace offers in the trim-size that I'll be using (5.25"X8"). I've also been playing with Cover Creator, a free and handy online tool for designing your book cover, and have high hopes for the final product. I've read through about 30 of their articles on the self-publishing process, which range from very general to amazingly specific.
As the process moves forward, I'll post about the good, the bad, and the ugly from my experiences with CreateSpace.