I did the 5K last year in 2012 because I wanted to get a feel of what back to back race days felt like, since I was doing the Goofy Challenge in FL a month later.
The course basically went around the parking lot area and the drag race portion of the Pomona fairgrounds. It was nice and simple and had a water stop or two on the course. You got a tech t-shirt and a medal (forgot to mention that in my half marathon review). You are able to do bib pick up on race day. If you’re racing on the Saturday and Sunday, you only need to pay for parking once. You just need to save you parking receipt for the next day.
This is a great race venue, if you’re just getting started in doing runs, such as 5K and half marathons. It’s a smaller venue, so you’re not overwhelmed by a massive amount of runners/walkers.