
Project Gutenberg is the largest collection of free books on the internet. Most of these books have been transferred to public domain status as a result of their age - so these books are truly free.
There are a few gems here. Things to make has plans for everything from a book stand to a model steam turbine. And wood joinery does not really go out of style, this books covers a variety of classic joinery techniques like dove tail and mortise and tenon joints.
1. Things to Make by Archibald Williams
2. Woodwork Joints by William Fairham
3. A Course in Wood Turning by Archie S Milton and Otto K. Wohlers
4. How to Make Mission Furniture by H.H. Windsor