Sometime around July (I think) is when they came out with a new stable version of CM10.1. That's when I installed it on the internal memory of my HD+. I've had no rebooting problems or anything. About the only problem I had was that I couldn't install the Nook app directly from the Google Play store. I had to download the APK and install it myself.
Anyway, I believe
this is what I followed. Just make sure you download the latest version and make sure it's CM10.1 and not CM10.2.