The Write Stuff Adventure is the best writing resource I have found. I just can't encourage you enough to obtain this great writing book. It's very affordable and will provide years of worthwhile writing projects that are really doable and enjoyable.
My high-schoolers never complain about the assignments, as they are very pleasant and realistic. This book really brings out the best in your student(s).
Check it out for yourself - I couldn't be happier with it.