Here's a previous post I made on a similar topic....
"Actually, there aren't too many places to spot. If aircraft are landing on Runway 19 (or departing on 1), you can get within a few feet...literally...of the taxi way on some side roads North of the field. They are kind of hard to find if you aren't familiar with the area though, but it makes for a really interesting vantage point.
Another decent option is the Laketown recreation area by the Treasure Chest casino. There is a big fishing pier out over the lake which gives you a nice view of aircraft on final approach onto Runway 19...about 1 1/2 miles out from the runway."
If you have a rental car, drive to the Wingate Inn (just North of the field) and then drive behind the hotel going back towards the terminal. You'll see the side streets, lots of light industrial in the area. Look for the big adult book store and drive to the end of that street.
It might be easier to find the pier by the casino. Leave the airport via the airport access road, take a right on Veterans Blvd, then take a left on Williams Blvd (the first major interchange you come to). Go straight down Williams for about 2 miles until you reach the lake. Easy to find.
Let me know if I can be of any further help.