Read all about it on the official site http://www.mcfc.co.uk/News/Team-news/2010/August/Mario-Balotelli-signs-f... as well as SSN and MEN links.
Note to Wookie: Tried the same method of inserting the official link as I did with the MEN and SSN links but it wouldn't work. Don't know how City's webpeople have done it but they've got a page link without a file extension but it works