That's actually not even a bad idea

Hint at it, not too obvious, not too subtle, like "If you want a few tips on taking notes, look at such and such"

As Dragon said, you should recommend it, but don't put to much emphasis on it.
Definitely don't force them to make groups (whether assigned or not). That just leads to resentment towards other students and the professor, and some students are forced to carry the work for the slackers.