Blurb is one of the largest Self-Publishing/DIY/POD digital book printers, and offers pretty clear (but somewhat biased) information about what they do.
Lulu is another self-publishing/DIY book printer, offering publishing options through Amazon.com – but they outsource the actual printing to facilities overseas.
Vistaprint offers a very wide range of short-run printed products.
Uprinting also offers a variety of of short-run options.
Mimeo specializes in brochures and pamphlets.
Print Place has a variety of products with many options for different sizes.
Print Access is a great listing of print and media resources.
You should all know of Remsen. They are local and are great to work with.
Here is another good listing of printer resources.
HERE is an exhaustive list of book printers.
Conveyor Arts is a local printer and publisher specializing in editions and short-run art books.
The Studley Press are fine art and commercial printers.
GHP is a very high quality offset lithography and digital printing facility.