The resources listed here are by no means exhaustive, but a great start to learning about traditional joinery! Also, be sure to check out the following video which does a great job showing sash joinery: The Trade of the Joiner
Book of Trades, or Library of Useful Arts - This is a children's book published in 1807, but provides great descriptions of all the trades to help them choose their future profession. Thanks to Google Books for making this available!
Joseph Moxon's Mechanic Exercises - Available online through Google Books. This is a must-read for anyone interested in historical woodworking or blacksmithing. This is a very early manual on smithing, house carpentry, joinery, turning, and making sun-dials published in the 1703.
The Woodwright's Shop - Check out Roy Underhill's extensive series on PBS. He does an excellent job showing how to construct things using only hand tools in an entertaining and highly whimsical manner.
Wood by Wright Youtube Channel - James Wright has developed a strong passion for working wood with hand tools. He presents traditional techniques in a very easy to understand and enthusiastic manner.