I started out buying old Williams S-wrenches. That stopped after I found the February, 1991 issue of Smithsonian magazine which had an article in it sub-titled "Old wrenches can be objects of beauty for tool collectors". The article had a picture of Elmo Rinehart's wrench collection. That sold me on antique wrench collecting (I had been collecting expensive railroad lanterns). Then I bought a soft-cover book, My First Thousand Wrenches by Donald Snyder. I read that through and through until I had memorized things that identified unusual old wrenches. I have read numerous wrench tomes since then, including Snyder's Second Thousand Wrenches, Cope's American Wrench Makers, Schulz's Antique Wrenches, Wullweber's The Antique Wrench Book, and P. T. Rathbone's The History of Old Time Farm Implement Companies and the Wrenches They Issued. I also read Martin Donnelly's Catalogs of Antique Tools which had 7 - 9 pages of usually high quality antique wrenches for sale. Finally, I joined the Missouri Valley Wrench Club, the Midwest Tool Club, the Early American Industries Association (EAIA). I still belong to the Missouri Valley Wrench Club (MVWC) since I have found its mission is closest to my interest in collecting old wrenches. The EAIA turned out to be mostly interested in colonial and post-colonial early industries, a lot of them related to woodworking. The Midwest Tool Club seemed alright, and it had regional meetings which MVWC does not. I still maintain a relationship with the Mercer Museum in Doylestown, PA which contains a massive collection of 18th and 19th century American tools and many other artifacts produced by craftsman and artisans of the time.
Tool Talk is a unique site, drawing together both new and experienced tool collectors. Reading the many posts will give you an idea of where to find tools and what tools to look for during your searches. This site will also assist you in developing a tool collecting focus, which you will probably be refining over time.