I am in the same boat you are. I drove OTR in the late 90s and then decided to come off the road to be with my family while my son was at home and in school. He's a senior this year so my wife and I are thinking about going OTR next year when he graduates. I have, however, been driving trucks since then. It's been local and in the construction industry.
I have been trying to get a company lined up for when my son does graduate from high school so all we have to do is roll. The problem I have been running into is that most companys want "recent" OTR experience. They don't mind a couple of speeding tickets, maybe an accident and some will even take minor criminal records. But you MUST have at least 6 months OTR experience in the last 3 years. The company's hands are tied due to the insurance companies.
Well, here is what I have learned in my OTR job hunting endeavors. Some companies will take you on as a student. That basically means that you will go through orientation and then out with a trainer for several weeks just like you were a rookie and fresh out of trucking school. If you haven't driven trucks in a while, you might have to go through a 40 hour refresher course. Some companies like Swift and Interstate only require tractor/trailer experience with a drive test as opposed to actual recent OTR experience. I have learned that some flat bed companies tend to be a little less restrictive. If you have any flat bed experience, you can get on with a smaller company and get your 1-2 years "recent" OTR experience and go elsewhere if you so desire.
The bottom line is that you're probably going to have to start out at the bottom of the pay scale and you might have to go to a less desirable company to start unless going out with a trainer is ok with you. I will not go out with a trainer that is barely out of trucking school. But that's just me. Good luck bud!