That's a really nice camera. (Y)
From what I know, 120 film is a medium format film that can produce pictures with very fine detail, because it is a larger film than the standard 35mm.
Normal cameras which everyone has used at some point are 35mm film size which is quite small. Large film sizes are usually 4-5 inches big and this would ultimately take better photos than a 35mm. 120 film, the one you want to buy, lies in between 35mm and the large film size and this is why they are called medium format films.
For example:
http://i13.photobucket.com/albums/a2...comparison.jpg
Edit: The 120 film is on the left, 35mm is on the right.
I'm sure most good photo shops will develop them for you.