What education do I need to become a professional pilot?

The simplest answer is you need a 4 year college degree and flight training up to a commercial pilot license.

A four-year degree will go a long ways so it is important you get a degree. Airlines like to see 4-year degrees and many require them, but the actual degree can vary. They do not generally care what the degree is in, they just to see want one because it shows a level of commitment and ability to learn.

I think it is understood; before you get too far into this career, make sure you quality for an FAA medical. Some things are allowed others you might not see as an issue can prevent you from flying professionally. If you are looking at becoming a military pilot their standards are even higher.
Flight Training: You have several options so it is really a matter of choice and how much you can afford to spend right off the bat.
You can go to an aviation college, and get the training along with the degree. Be careful with what type of degree you get, although you do not want to think about it you need to ask what happens if you cannot fly or want to change careers, you should think about what backup education you may need.

Depending on your program, you can expect the cost to be equal to private college tuition.

Get your 4-year degree not in aviation, and then attend an accelerated program such as ATP or Comair Academy, where you will get all the ratings in about 3-9 months.

Go to your local flight school, and take the training there. This can be a bit daunting as these programs are not set up to train professional pilots quickly. They are more designed to teach the local moms and dads to fly for fun and often can be more social club than anything else.