1. Check as many websites as you can but be aware it is not inexpensive. I am finding the rates close to double last year.
2. Sign up for email alerts and join the club. For Dollar Rentals it will allow you to avoid the lines at the rental facility. I believe most of the companies have the same thing.
3. The rental facility for all companies is one building away from the airport with one shuttle for all the companies. It is very well run and takes just a few minutes to get there.
4. All hotels have free parking. If you valet you just have to tip. You may want to drop your friend off at an entrance and then park. Decide which ones are closest to where you want to be inside (front door or parking garage door).