A good working relationship with a printer can help cut the cost of your print projects. But first you obviously need to find a reliable vendor. I covered a few basic money-saving tips deep in the archives, and previously featured your recommended UK commercial printers. Here are some additional resources.
Jessica Hische added a “find by location” tool to Inker Linker (worldwide, but with US focus).
Lovely as a Tree contains a UK database of commercial printers.
Rob Giampietro published a list of mainly US print vendors (some within Europe).
Tina Roth Eisenberg shared US-based letterpress studios (with many more in the comments).
Designers & Printers is a free directory where print companies list their services (broken link removed, 2015).
Woodtype specimen photo by Grant Hutchinson.