You have a few choices here
You can go the ultralight route, or as I like to call them "flying lawn chairs". They also come in the form of powered parachute. This is the cheapest way to go as far as training is concerned, since no training is required. Still, it's a good idea to get some basic instruction. The aircraft themselves can be bought or built from kit fairly cheaply...about the price of a good used car. You can find new or used on ebay, craigslist or in Uncle Henry's. Be careful buying used. You don't know who built it and maintained it , or how, and there are no inspection or certification requirements.
Next step up is the Sport Pilot certificate. A bit more expensive, because you have to take actual lessons from a certified instructor, and prove to an examiner that you are safe enough to get an FAA license. Not a bad thing, in my book. It allows you limited daytime privileges in a very light plane to carry yourself and one passenger. The airplanes must be certified and inspected, so they are more expensive to own and operate, but they are available to rent by the hour, so in the long run renting may be more cost-effective than owning. I think the cost of training to licensure is $2 - $3k.
From there you can go to Recreational Pilot. More training, more money, more privileges. After that is Private Pilot.
Try the Experimental Aircraft Association website,
www.eaa.org for good basic info on low-cost flying. Also hang out at local airports and ask questions. In your area, there is Biddeford and Sanford for a start.
If you want an adventure, come on down to Sanders Field in Greenland, NH the first week in July. They will have their annual Yankee Flyers Ultralight Fly-in. A week of camping, flying and story telling, plus up-close and personal exposure to the men, women and their machines.
