Back in '08-'09 the Mrs. and I did one bathroom, a kitchen, and turned a half-bath into a full. Hired a contractor. Got lucky, he was FANTASTIC! I pretty much did the design, he and his crew made it happen. Not everyone gets as lucky as we did, I've heard horror stories about contractors...
If you choose this route, I suggest interviewing more than a couple. Ask for references with phone numbers. Call them, ask them about their experience. Visit their homes and look at the work if t all possible. Ask the contractor to see photographs of his work.
"I am allergic to piety, it makes me break out in rash judgements." - Penn Jillette
"I have never killed a man, but I have read many obituaries with a lot of pleasure." - Clarence Darrow
"The man who invented the telescope found out more about heaven than the closed eyes of prayer ever discovered." - Robert G. Ingersoll