I have two cars, is it possible to rent out my second car every
weekend.  Its a late model nissan maxima, I'de like to rent it out but
I'm worried about what will happen to it if it gets into an accident,
I was wandering how I can setup insurance so I can rent out this car. 
Also, what other problems could arise?

#1.  Check your state motor vehicle law for the requirements of being
in the rental business.
#2.  Form a business corporation - you don't want to be personally
liable if anything happens.
#3.  Get a business license from the city/county.
#4.  Tell your insurance company what you are going to do and get an
big jump in your automobile insurance.
#5.  Go rent a vehicle and keep a copy of all the forms they use.
You'll need to use similar forms.
#6.  Decide where you are going to advertise and how much you can
charge for the rental keeping in mind what the competition is
charging.
#7.  What do you do if the car break downs miles away from your home. 
Who do the renters call for service and how do you replace the vehicle
they've rented?
#8.  Have a beer and think of another business to get into.