There are 36 tutorials. They range from simple beginner-level info, such as how each piece moves and captures, to more advanced, such as En Passant, Castling, endgame strategy, and so on. Some play themselves. They're easy. They take about 20 minutes to do, and if you fail one, it'll ask if you want to re-try it. This is essentially a free achievement and you'll get others along the way, should you not have them yet from other matches.
For example, I obtained En Passant and 100 pieces captured while playing through the tutorials.