The park is a good retreat inside the city. The kids will enjoy feeding the ducks in the lake, if you can keep them out of the zoo for a moment.
Take the St. Charles street car to the north end of the park. Pick up the free shuttle to the zoo at one of the shuttle signs. If you're driving, you'll find plenty of parking in front of the zoo at Magazine St..
The park offers group shelters, jogging/bike track, amphitheater and plenty of shade.