Here are some of the more explicit DVDs with strapons.

Straight videos:
Bend Over Boyfriend- Carol Queen gives very clear instructions
Bend Over Boyfriend 2 - More rockin’, less talkin’

Lesbian videos:
The Crash Pad Series Volume 1 - New from Shine Louise Houston
Full Load: Scenes from ssspread.com - Vignettes and explicit strapon scenes
Hard Love and How to F*ck in High Heels - Lots and lots of dildos in all different colors
Suburban Dykes - A classic with Nina Hartley