How do you choose safe video games for kids

Video games come with a rating on the back and front that tells what age range the game was intended for. There are several ratings, and you usually see them in a small black box on the bottom of the page. On the back of the game there should be the rating and why that rating was given (ie, mild violence, mild language). Here are some of the ratings, and the ages recommended for them are in (parenthesis).

EC- Early Childhood (3y+)
E - Everyone (6y+)
E 10+ - Everyone (10y+)
T - Teen (13y+)
M - Mature (17y+)
AO - Adult Only (18y+)
RP - Rating Pending (this one is only seen on advertising before the game has been released)