Numerous books and online sites offer instruction in how to do various printmaking techniques. You can find the books in the library by searching for "Printmaking--Techniques" or under the specific mediums such as "Lithography--Techniques." A recent series of handbooks from the British publisher A.C. Black include titles like Colour Etching by Nigel Oxley, Digital Printmaking by George Whale & Naren Barfield, and Hybrid Prints by Megan Fishpool. Listed below are few additional suggestions: