The sale of any vehicle should start by getting a reasonable estimate of its value. Kelly Blue Book or Edmunds are two trusted sources for car valuations. In fact, you should get estimates from both sites.
Enter as much detail as you can about the car in order to get the most accurate value. You should focus on “private party,” since this is the sales route that you will be taking. They also provide “trade-in,” in case you want to go down that path, and “dealer retail,” which wont apply since you aren’t an auto dealer.