8GB Ram upgrade and stock ram.

My dad has recently given me his old Macbook so I can start programming in xCode, and although it wont be the fastest machine it still gives me a Mac to work with. Its currently still being sent to me in the post and I was wondering 2 things:

1. Does the Macbook Pro come with 2 sticks or 1 stick of ram. I want to know this so I can purchase another stick or if i'll have to order a matching pair for the machine
2. Is there a specific type of RAM I should be buying? If so what type and wheres the best place to get it in the UK?