If you really want to understand your rabbit, the articles that Shawn linked to are great. :thumbup
I also recommend just watching your rabbit. Get on the floor and look at them, a rabbit looks completely different face to face. I can tell when my rabbit is going to growl at me, she puts her whiskers forward and gets this look on her face. You will learn the subtle rabbit language over time. This is great to know because rabbits tend to mask their illness, until it is an emergency. Learning your rabbit's body language will also make it easier for you to bond with your rabbit.
Good Luck,
~Star~