Keith:
The first one takes a while. But, after you have a form built and build one bow to get some hands-on experience it actually goes pretty fast.
I didn't buy any plans or a kit, but that would be a faster way to go. Check out Kennys Custom Archery (sponsor). He has a good write-up on building a form, is a great supplier of wood, glass, & glue, and has an inexpensive template that many guys have used to get started. I built or modified 4 forms before I got a keeper.
It is addicting and there's always something new you want to try on the next bow.