As far as I'm aware there's no easy treatment of egg binding. What I've heard suggested is simply giving the bird a light massage to coax the egg out. Taking it to a warmer room or giving it a warm bath is supposed to help too. It's all about relaxing the muscles to help the egg pass.
If you can't coax it out on your own, then the only "treatment" is to take the bird to a vet where they will try to coax it out, and, as a last resort, break the egg and remove the pieces by hand. If that happens, it's important that the bird, and anywhere it is for the next few days, is kept clean, as the risk of infection is incredibly high.
I don't know if the causes have been actually figured out for sure yet (hopefully someone with more knowledge on birds than me can chime in later), but the most accepted explanation is calcium deficiency. Making egg shells takes a lot of calcium, for both birds and reptiles. There are many different products to help your bird keep a healthy intake of calcium. The most popular I've seen are cuttlefish bones. I've heard of ground up eggshells being used too.
I've also heard some suggestions that it might be other influences in their diet, such as a seed-only diet. Something that's not natural for most birds kept as pets.
Another suggestion I've heard is that it's caused by the sedentary lifestyle most pet birds lead. Since most pet birds live in a cage, they don't get to spend a whole lot of time flying; definitely not near the amount they would in the wild. So it's possible that a healthy exercise routine and a healthy diet could help you to avoid ever having to worry about having this problem.
You'll probably notice signs of depression more than anything else. The bird will probably stop eating, and could either pass larger droppings than normal, or none at all, due to the egg interfering with the intestinal tract. I think that most commonly, they will sit at the bottom of the cage fluffed up and straining in a way that looks like panting.
Here are a couple links that should hopefully help understand what I've said, and maybe even give some more ideas on how to prevent/treat it.
avianweb.com/eggbinding
tailfeathersnetwork.com/birdinformation/egglaying
