restoring

Afriend recently gave em a dinng set which includes a table, four chairs and a buffet. She said it was made in the 1930's. It is a very dark brown/black wood. It is good shape but needs some attention. The top of the buffet has indentions and black marks. The table has a white water stain and an inpression form a table cloth or something like that, the chairs alsohas some nicks as well. I wanted to know how to go about repairing these form the point of never have dealt with this before. I do love the set and want to keep its dark coloring.