Content Background

Gravity - a nice handout explaining what  Newton's Law of Gravity is qualitatively and quantitatively

Kepler's Laws - Chapter Four Section one of this site is an excellent backgroung for understanding Kepler's laws.
 

Below we have listed some other good sources of background information,

Online Information:

Highly Recommended Teacher Background:
http://www.glenbrook.k12.il.us/gbssci/phys/Class/circles/u6l3a.html - The Chapter 3 and the rest of Chapter 4 are also excellent background.
http://www.star.ucl.ac.uk/~idh/STROBEL/gravappl/gravapplb.htm  - Background that starts with forces and moves through Kepler's laws

Interesting Additions:
http://spaceprojects.arc.nasa.gov/Space_Projects/SSBRP/gravity.html   - Some interesting gravity questions with their answers, like can you make an anti-gravity room.