Community questions

I am helping a friend with his community garden plot and we decided to experiment a little bit. A week ago we covered the soil with coffee grounds (about a half centimetre) and about 2-3 layers of paper/newspaper, added compost on top of it and then some dried leaves. This is a kind of sheet mulch - we just didn't want too many layers because it would have gotten too hot (for 1-3 weeks) and...