Some very good responses. Here is our experience with leasing our home out for 7 years while we traveled fulltime.
We were fortunate in that my stepson and his wife live across the street from us and rented their home from us! Our daughter-in-law acted as the "rental manager" (we had another rental house several blocks away) and had repairmen lined up if needed.
If your not that fortunate, by all means, go through a rental agency.
Second, and most importantly - no matter how good your think your renters are or will be, they will very seldom maintain your home and property they way you would. Just realize that there will be painting and flooring replacement to do when you move back in, if you do. We did and even though we only live there during the summer, we are still getting caught up with that and getting the yard back in shape!!
I forgot what or if you mentioned what you were going to do with your furniture. Get rid of it!! Storage fees alone will buy you new furniture when you move back in!! We know!! :B Only store or parcel out what is regarded as family, irreplaceable heirlooms.
With the improving real estate market, you may want to consider selling and stashing the money to go back into a home. After you spend a winter down in the south with the sunshine all winter, no snow or rain, why go back to it?!? That's why we are now in SC and love it!
Good luck with your decision and enjoy your travels. We loved our fulltime travel experiences.