How strong are you now in chess? Not very. I know what each piece does. I could play a game with a stranger and think critically enough to take some pieces. I don't know anything about tactics, or openings, or anything like that. I think anything just above how the pieces move is knowledge I could use.
if you have an iphone, then chessimo would be perfect. I thnik with chessimo, you might actually do the puzzles, whenever you have a few minutes (which is why the mobile version is so good). using a chess book properly is a skill in itself.
play some games here...then review them to see what other choices you had for each move....chess is choosing the best outcomes...
show us some of your games....
are you going to use a clock?
do you know how to mate quickly with a K and Q vs K?
how about how to convert a K + P vs K?
what are the requirements to win those endings...very common...