Hey Joe,
I think you'd be hard pressed to find any resources that talk about giving personality to a ball specifically ( because I'm trying to think of some.) What you will find everywhere are resources that talk about giving life and personality to inanimate objects.
Okay so think of it simply, what are some of the aspects that help you to distiniguish a happy little boy from a melancholy one? You'd expect a happier kid to be boucing of walls and maybe he'd have a little spring to his step. Faster movements maybe? A sadder one would be a little slower and mopier right? Maybe minimal movement? Not as bouncy?
However cryptic that example may be, my point is to think of familiar instances you've observed in life of people behaving in certain ways, and try to mimic that with your inanimate object you have on your screen, or in your case, a ball.
Good luck.
ps, have you tried Cameron Miyasaki?
just kiddin.
