A short series of hints would be much more helpful, that's great. Also, at least one of the exercises (I'm thinking of mating with a rook and the king) puts you back to the original starting positions if you make a stalemate move. A bit frustrating to have to go through the beginning all over again.

I haven't played in at least 10 years and so far it's been a nice refresher, and a good looking site as well.