The exercises idea is not a bad one. I have been translating some of Perl documentation to Lithuanian and one of the requests from the readers was to provide some exercises.
However this applies more to the beginners exercises. I find that solving problems and helping other monks helps me a lot in learning. I do understand that most of the questions in the monastery are too difficult for beginners and we might need a special node or section for beginners exercises (but then again... Categorized Questions and Answers is almost liek an exercise book (with answers!)