Much of this depends on where you live and what your eventual building interests are. There are a variety of courses out there from the simple several weekend courses often offered at Community Colleges and at marine museums, such as the Chesapeake Bay Maritime Museum in St. Michaels, Md. or The Mariners Museum in Beaufort, N.C. to the more professional courses like the Landing School, and the WoodenBoat School which require a more substantial amount of commitment but which turn out professional boat builders.
If you are not near a school that offers boat building course, there are a number of very good books on the subject out there. They vary between Howard Chappelle''s "Boat Building" which is still an excellent resource for traditional wooden boat building, to books like Gougeon Brother''s wonderful book on cold molded wooden boat construction. Chappelle''s book contained enough information that I was able to build my first boat without ever having taken a course. There are also books out that describe how to build a specific design on a step by step basis.
I also learned a lot from working in boat yards as a kid. Boat yards don''t pay much but you can get to see a lot of different types of repairs. In many areas of the country there are small boat cooperatives where you can rent space and build a boat. Typically, there are enough experienced folks that you can get a lot of free advise worth far more than you pay for it.
If I were to give you a couple pieces of advice that I have learned the hardway or seen others learn the hardway:
1.You will not save any money at all by building your own boat so you had better enjoy the process.
2. Learn to sail well and experience a bunch of boats before deciding on a particular boat to build. All too often, beginner sailors lock in on some design and spend years lovingly building this design, only to find that it is ill-suited for thier needs. There is nothing sadder. I have taught some of these people to sail their boats when they are finished.
3. If you are new to boats and sailing, do not try to invent a new way to build a boat or choose some odd ball design. There are probably very good reasons why no one has used that method before, or why most boats out there do not look like the oddball design, and until you have some more experience those reasons may not be obvious to you.
4. Don''t be afraid to build something once with cheap disposable materials to see how it works and to make patterns before building it for real with the good stuff.
All of that said, if you have good eyes and good hands and are not afraid to take your time, you should be able to build a good boat.