Here’s a little info from Safeco Insurance about letting your teenager obtain a learner’s permit:
A learner’s permit is a restricted license given to someone who is learning to drive but has not yet satisfied the requirements necessary to obtain a driver’s license. To get a learner’s permit, one must typically pass a written test about the rules of the road. Normally, one is required to have that learner’s permit for a certain length of time before applying for a full-fledged driver’s license. (Driver’s education, a practice log and a road test may also be required.)
In the U.S., the minimum age for receiving a learner’s permit varies by state, ranging from 14 to 16. Normally, someone with a learner’s permit may only drive with a person who has had a driver’s license for several years. If the learner is a minor, he or she must have permission from his or her parent or guardian to obtain a permit. It’s important to obtain the latest documentation on learner’s permits from your state’s Department of Motor Vehicles (DMV) because age requirements and laws differ from state to state.
You can usually download DMV manuals from your state’s website.