The best book of all is Brian Brennan Spartan Society Interpreting the Evidence. Its great. Our school got a set but I think you can buy it in town. There are pages and pages on Sparta archaeology and sites and it has all the latest ideas. Our teacher says that it completely disagrees with a lot of the crap that has been written on Sparta - this dude claims that Plutarch is crap, there is no kleros, that Spartans were architects and craft workers, that they used the coinage of another place and that the iron money stuff is just a rubbish story. He lists the Spartan military defeats. Basically its very different and our teacher reckons those who use this information will be miles out front of those with the old stuff which has been taught for years by lazy teachers