Back in 3rd grade, my class was given group lessons on recorders.
Record. Stop. Rewind. Press play. Stop. Fasssssst forward!
Rewind! Seriously, rewind... Not that type of recorder!
I found a neat little set of 10 recorder lessons for kids at Rockin' Recorders. There is a printable pdf, but you can also view the 19 songs online. They have a set of songs for the students, and teacher lesson plans, teaching transparencies, and a pre- and post-test.
I bought two recorders at the Dollar Tree (Two for $1!), and started these lessons with my boys. Elijah has a hard time reaching the holes on the recorder, but being in Kindergarten, that makes sense. He's still a bit young. Cedric has learned the first 3 notes so far. He was very excited to "play" Happy Birthday to Elijah at his party, even though he didn't hit the right notes at all, he got the rhythm down. That's good enough for now!