I read an interesting article in the IBPA Independent, a monthly publication from the Independent Book Publishers Association of which I (RJBP) am a member.
It's all about getting your book to as many selling formats and venues as possible. In his article, Gordon Burgett calls it ancillary publishing. And this is not only for independent publishers, but authors as well.
First of all for bound books, listing through Ingram's Lightning Source division, which is a wholesaler/digital printer that is available to individuals as well as independent publishers, is imperative. It also provides fulfillment and distribution services at whatever level you wish - distribution channels are Amazon, Barnes and Noble, Baker and Taylor, and others. They are my primary wholesaler/printer at the moment until RJBP qualifies for an additional with a broader base. $$ are received on book sales after costs of printing and the discount percentage you offer to booksellers has been deducted. If you are a self-publisher, it would be to your advantage to sign on with LSI. Title setup costs vary, and it is $30 for a proof. You must have your own ISBN.
Next comes Createspace.com, a subsidiary of Amazon.com, or is it the other way around? It's smart to use them as a secondary wholesaler/printer for bound books and e-books because they will immediately put the book up on Amazon.com and will handle distribution/fulfillment/printing for you. You will also have the direct line to Kindle through Createspace. The cost is $50 per title setup on Createspace - that's for the better break on printing costs, zero otherwise. A proof usually costs around $12 including shipping. You don't need your own ISBN on Createspace, but of course if you list with LSI you'll have your own.
(Just want to add here that ebooks account for a very small percentage of the bound book sales. So getting the bound book out there is imperative.)
The article also suggests using LuLu.com for additional exposure to the extensive Lulu Marketplace that you wouldn't have otherwise. I don't use Lulu at present, but I believe I'll look into that for my clients. So, if that option is available, it's a given that I'll add them to my list of wholesalers/printers.
At this point, you'll have three companies printing your books to order and you'll have broad distribution on the Internet and books will be available to booksellers. Just by using these three sources, you need do nothing else, for they will fulfill the orders by you or by the public using their facilities.
If you are an independent publisher, it's also good to have a full-run printer as your major source of books-on-hand to sell directly to booksellers and libraries, such as McNaughton and Gunn, or Patterson Printing, or Rose Printing, or your choice of many other short/full run printers, maybe even one in your own geographical location.
So that's it for the most expedient ways to get your book out there ... more on ebooks later.