I’ve been attending the Air Races since 2001 (although they didn’t race that year due to the events of 9/11).
First off, seating in the grand stands (general admission or reserved) is hard on the fanny and back, so consider bringing a good cushion and/or seat with back support. I usually opt for general admission on weekdays and reserved seating on Sat and Sun. Both offer good views above about row 6 or so – higher is better to see over people who can’t seem to put their butt down during the races.
There are several pay parking lots and very limited on street parking unless you are a real early bird and know the area.
If you want an up close look at the race planes, you’ll need to get a pit pass. I usually do the pits on Fri before things get too crowded and one day is plenty.
Do NOT miss the static display for up close viewing of some amazing restorations of historic, rare and old air craft as well as current military planes of all kinds. Check the view of the races from the fences here for a view of the planes rounding pylons 1 and 2.
Warning – weather is extremely variable. One year the weather was clear and hot (90+) on Wednesday, Thursday was same but maybe in the 80’s, Friday was in the 70’s maybe, Saturday was cool (60’s?). Sunday was just plain cold with a snow storm coming over the mountains. By the time of the final, big race (unlimited gold race) the planes were flying through snow on the west end of the course. Bottom line pack shorts and a heavy coat.
There are plenty of food vendors and bring lots of money if you’re into souvenirs and mementos.
PS - there are lots of Port-a-potties. If you encounter a long line, walk down the line and you'll usually find on available further down toward the west end.
If you're rolling in dough, check out the Checkered Flag club. I opted for this a few years - seating in plastic chairs, free lunch, free drinks, noon speakers, private toilet facities and absolutely the best parking at the races but you'll pay dearly for all this.