I am currently writing a 2D space shooter in which each player controls a ship that is ball shaped, the best explanation of ball to ball physics I have found is:
http://freespace.virgin.net/hugo.elias/models/m_snokr.htm
I am posting it here partly to thank Hugo Elias, and partly to help others who may be having a similar problem.

Correct me if I'm wrong, but this seems like a highly simplified version of the problem. All it deals with is momentum. We don't have any explanations of how to solve the remaining problems of rolling and friction. And what if the pool table is slantd? How does it account for slopes

You seem to misunderstand me.
By excellent, I meant simple to understand for somebody who's not a professional mathematician.

That's what happens when you make up your own meanings for words.

It doesn't take into account when a ball is spinning and collides with another ball.

I love stuff for stupid people!

Well I'm sorry if it's too simple for you all .
I posted it because it's the only explanation I understood (and even then I had to go and find out what dot products are normalising were).

That is the basics, but it is cool.

I actually was being serious. I do love stuff for stupid people, as I consider myself one of them. I do see how my comment could have been taken as sarcastic though...

I gave up on my football game in the last world cup because I couldn't get the ball physics right in the time I alloted myself. In particular converting friction into spin when the ball bounced on the ground was where I stopped coding and started dreaming about a general purpose ballslib.

If it had been a serious project I would have tried to use the Bullet physics lib.

Well, to complete this topic and avoid people to get frustrated, given the title, I would like someone to put a more specific and useful link.