You've got the book written, edited and proofread, the administration done and a beautifully designed interior and cover. You're only one step away from having that precious book in your hands: printing.
When it comes to printing – you will print, won't you? – there are basically two choices available to you: short run (aka 'digital printing' or 'print on demand') and long run (aka 'offset'). Your choice will depend on how many copies you want to print, which in turn will depend on how many copies you think you might sell and how much money you want to spend up front. Often – but not always – you will want to print an initial short run to test the market.
As with design, book printing tends to be a specialist field within the broader printing industry. Whoever you use to print your book, you'll generally be better off dealing with people who print books, rather than brochures, for a living.
If you are printing less than 500 copies, and especially if you are printing 100 or 200 copies, you'll want to use a short run, digital 'print on demand' (POD) printer. These printers essentially use fancy photocopiers (they'd hate me saying that) to produce the inside of your book, and fancy colour printers (inkjet or laser) to produce the cover.
This being the digital age, you will generally email the printer two PDF files (one for the text, or 'block', the other for the cover) and they will do the rest. Your designers should be able to supply you with files in the format specified by the printer (and if they can't, get the designer and printer to nut it out directly in language they both understand and you probably don't).
Short run copies of your book (let's say it is 200 pages) will cost you around $5 to $7 each to print, though less expensive options can sometimes be found. This is a fast-changing, competitive industry and costs are coming down all the time.
Online companies like Amazon are increasingly moving to a model of 'printing to order'. It is already possible to have your book listed on Amazon and printed to order using their CreateSpace service.
If you are printing 500 books, it is probably worth getting a quote from a long-run printer too. For 1,000 or more copies, this is probably the way to go.
These printers use more traditional (albeit a modern version) 'offset' printing. Printing plates are produced for your book and these plates are used to apply ink to the page.
Offset printing is of high quality and the actual printing cost is relatively low. But there is a significant up-front set-up cost in the production of the plates. For this reason offset printing only becomes cost effective for longer runs.
Also for this reason, you will notice that the cost per copy decreases rapidly the more copies you order. For example, a recent quote for 1,000 copies equated to about $3.80 per book, but 2,000 copies came to only $2.60 per book.
In fact, as with most things, it is worth shopping around for printing. However, as with most things, you also get what you pay for. Personally, for instance, I prefer paying a little bit more to be able to deal with a local printer.