The main reason to visit Mai Chau is to take one of the treks to minority villages around the area. You can arrange a trek at many of the travellers cafes and hotels in Hanoi. Mai Chau itself is rather spread out and is actaully a collection of villages rather than a town but this adds to its appeal.
There is no direct bus service from Hanoi so the easiest way to make the 135km journey is by minibus belonging to one of the tour groups in Hanoi.
Below is a list of hotels in Mai Chau sorted by price range (highest first). If you wish to telephone a hotel the area code for Mai Chau is 018 (+8418 from outside Vietnam).