well i have to add my two cents here. I'm a student on co-op in a major 8051 company, i also worked on the 8051 in college this year. while i'm fairly competent at programing it, at the start it was very hard and the stupid questions need to be asked. To be honest, while the tutorials are fine to explain the programs, i found it a bit hard to implement them practically, e.g. for just sending and receiving data over the uart. a mentors corner would be a good idea
I have the art of electroincs, while very good it is pretty sketchy in some areas and a bit too advanced in others. otherwise an excellent tool