| Most books on guitarmaking describe the scarf joint. It's hard to explain in words, but essentially, it's a way of joining a tilt-back headstock to a guitar neck. The alternative is to cut the tilt-back headstock from a single, thick neck blank, which results in considerably more waste.
I recommend not worrying about the scarf joint on your first instrument. Once you have some experience, you can worry about whether the scarf joint is the way you want to go. | 
