I am a dog park proponent. I realize the dangers, but there is danger in everything, and the reward in dog socialization and exercise is worth the relatively low risk in my view.
I agree that you should go by yourself first and walk around in the park when it is crowded with dogs to get a feel for the dynamic. You will need to be at ease when your dog is there, so you need to experience it first. Our dp is in Houston, and in the 10 or so visits we have made we have yet to see even ONE repeat dog there, so based on my experience you will not be able to get a feel for certain dogs that you can rely on seeing over and over again.
Everyone (98%) is in the same boat as you: they love their dogs, they are nervous about having a bad experience, and want to observe the unwritten etiquette. This means they will be conscientious and considerate in handling their dogs. Also, the dogs have usually been socialized and get along well. Invariably, the indicator of a "problem" dog is one where the owner says "this is our first trip here" or "he's never been around dogs before". By breed, there is no correlation with which dogs are "nice"--so leave your preconceptions behind.
Don't bring treats. Don't expect other dogs to leave your dog's ball, toy, etc. alone--it is a free for all on the balls. Amazingly, I have seen that most dogs are very respectful of other dogs chasing a ball or toy--the only problems are when there is a dog that brings and is obsessed with its own toy (owner error).
I have seen no serious fights, just a few growly moments. The quickest problems seem to develop when a dog chases another, and the prey drives kick in and several others join the chase. These usually end in a abrupt stop by the chasee, lots of butt sniffing, and then everyone trots away. However, sometimes there is a tackle and roll, a snap and snarl, and it gets a little testy. Relax, they usually work it out themselves and stop, and then sometimes the owners standing nearby break it up.
You want to watch out for your dog's safety of course, but you don't want to be a "helicopter mom" (it helps to have raised kids to get a feel for this). Don't try to follow your dog around and intervene in every encounter. You can't micromanage the dog park or your dog, and all you will do is communicate uneasiness to the dogs and irritate the other owners by doing this.
Good luck and have fun with it!