I'm starting from zero here, I know basically nothing other than that they started in Italy and there was a strong distinction between guild labor and unguilded labor, and thus guild craftsmen and unguilded workers. I am interested in that, as well as their relationship, if any to the peasantry in particular and society writ large. Thanks!
The standard work on the subject is probably Steven A. Epstein's Wage Labor and Guilds in Medieval Europe. While I haven't had a chance to read it yet myself, the reviews are overall positive. Germany is apparently almost entirely ignored, while parts of the Low Countries and Rhineland receive less focus than they deserve and the chapters focusing on the early part of the Middle Ages are also apparently somewhat weak, but the "classical " period of the guilds - the high middle ages - is very well documented and discussed.