Well Kristen there's a thread in the main forum where people gave their "top 10" list so you might want to look for that. Personally I would recommend the Tao Teh Ching, the translation I have is by a John C. H. Wu published by Shambhala, though there are other good versions I'm sure. Just don't get Stephen Mitchell's, and look to see if it's a literal rendering - Chinese is a completely different language. This thing is very short (you can easily read the whole thing in one sitting) but you can get a lot out of it if you stop and think about it a bit. It's not religious per se but a philosophical work, religious Taoism is quite different. If you check it out let me know what you think.
By the way, I'm glad you asked about something to help your growth after leaving the organization as opposed to helping you break free. No doubt most will have a bit of JW thinking pattern left, but I think one of the most effective things you can do is to stretch your mind in order to go beyond that pattern.