If you're looking for a large pool most people seem to be using Suprnova (https://rvn.suprnova.cc/) or Ravenminer (http://ravenminer.com/).  But it is probably best to try a few different ones to see what works best for you.  Probably can't go wrong giving one of these two pools a try to start out with.

If you want a medium or smaller pool best bet is to just go through this thread identify them and then check them out.  There are a lot of smaller pools out there. 

Good luck