this is taken from the florida state troopers website
Step 1: Babies from birth to one year AND 20 pounds ride in rear-facing child seats.
Step 2: Toddlers from one year to age four (& 40 lbs.) ride in forward-facing child seats.
Step 3: Children ages four (& 40 lbs) - eight (or 4'9" tall) should ride in booster seats.
Step 4: Children over age eight (or 49" tall) may use vehicle's seat belt.
ALL children 12 and under should ride in the back seat of a vehicle.
hope this helps