Consider nursing.  They are always in demand and the future looks bright with the aging of the population.  They have work hour options like 12 hour shifts for 3 days which equate to 40 hours, then 4 days off.  From nursing homes to hosipitals to doctors offices and schools, the demand keeps growing.

Additionally, I hear that they are still paying signing bonus' to experienced nurses who will shift from one employer to another. 

Good luck!

I am by no means an expert, however when it came to school I always had one rule:  crunch the numbers.  I have watched a number of friends make the mistake of not crunching the numbers - going to expensive schools and getting a degree in a field that is either not lucrative, not in demand, or both. 

At the very least, what you go to school for has to provide the earning potential to recoup your financial investment, within the amount of time that you plan to use that degree in the professional world. 

Figure out what you want to do professionally after you finish school, if you decide to go.  Use an online salary calculator to see what people in your area in those positions are currently earning (I think they even have one in the career resources section of this site).  Find the difference between that and what your current earning potential is. 

Then figure out how much school will cost you (which should include interest if you will be taking out a loan and/or opportunity cost if you will quit your current job while in school).  Subtract one from the other and you should have a pretty clear picture of whether going back to school is a good financial decision.