This about covers it right here:

http://www.techguys.ca/howto/winter.html

Granted you aren't storing the car for winter, but all of this applies to long-term storage as well.

As far as places of storage, just start calling various storage areas in the area. Make sure it is in some sort of locked compound as many have storage units outside the locked/fenced area.

Here is where I have a storage unit for misc shit. Seems like a great place to store a car as the area is locked, the manager lives on the grounds, and there are always people there working out of their units (i.e. many eyes looking for suspicious activities):

Discount Mini Storage
Address: 3820 W Fair Oaks Ave, Tampa, FL 33611
Phone: (813) 839-4773