I realize your question was asked back in 2009. But for the sake of others wondering about the same thing in this wonderful neighborhood, here are some of the answers:
The HOA in Hollywood Park is optional. Currently the dues are $20.00. These dues help fund a variety of community events throughout the year. Participation in those events is not always dependent on whether or not you've paid the dues.
The Voigt Center includes community amenities including a large playground, tennis courts, a covered picnic area, and a pool area that is home to the Hollywood Park Hammerheads swim team. The pool can be accessed by residents with the purchase of a season pass available at City Hall.
There are no set jogging trails, however, with the abundance of trees and wide streets, many use the streets of Hollywood Park to run, walk, or bike.
Hollywood Park does have its own Fire & Police Departments as well.