Been there, done that (seven year gap!). I did find the OM of my ATO very usefull for relearning regulatory requirements of flying. (I also red paco's book, you won't go wrong with that one) When you start flying again, try to fly at least 10-20 hours in the first month to regain routine of flying. I was only flying 10-20 hours spread all over a year for couple of years and it was quite miserable time. But it all ended well for me, I'm sure that also you can do good!