Never heard of one before. It's not like building an engine or anything, it's actually simple. ARs are the "Level 1 Snap Tite" model of the gun world.
If you can assemble Ikea stuff, you can put an AR together, no problem.
Colt runs an armorer's course, as does S&W, and likely others.
Yep AR's you assemble AK's you build
Check this out Learn How to Build Your Own AK with the Rifle Dynamics AK Builder Class : ITS Tactical