Hello, I'm Callisto and I'm new here.  

Here's the background on my hair--it used to be long.  Waist length when dry, hip length when wet.  Unfortunately, I was a tomboyish 6th grader at the time and have since cut it back to shoulder length to remove the unhealthy bits.  Now it is midback length (waist length when wet) and curlier than ever.  The mass of it is very thick, even for curly hair (if I braid it the braid is about as thick as my fist) and each individual hair is fairly thick as well.  I was wondering if you had any suggestions for me to grow it out without having the trouble I had last time.

Hello Callisto, welcome to the forum :)

Jerry

Welcome to the forums :)
I also have very thick curly hair. It is not nearly as long as yours however, so I hesitate to give any advice.
Have you read The Cury Girl Handbook? It is amazing and helped me a huge amount. Also jojoba oil on the ends and aloe vera lightly, as well as crystal hair mist, are all very helpful.
Shampoo is not your friend! I think I shampoo once or twice a week in the summer, and almost never in the winter (what can I say, my scalp is more sensitive to cold weather and stops making alot of natural oil)
I apologize if you already knew all this.
Happy posting!~

The Curly Girl book and our resident curly heads here can give you lots of suggestions for growing out healthy curly hair.  One thing you have going for you right now - your age.  You are more mature now than your were when you had long hair before, and therefore will take better care of your hair.  Also, your hair is entering its fastest growing phase (mid-teens to mid-twenties).  

Curly hair is dryer than straight hair so you need to pay attention to conditioning your hair and keeping moisture in.  You are already using shea butter on the ends - keep this up!  Minimize the amount of shampoo (if any) that you use on the length.  Only the scalp really needs the shampoo.  The less you mess with your curls, the better.  Let your hair air dry.  Don't brush those lovely curls.  Finger combing is probably best for your corkscrew curls - a wide toothed comb when the hair is damp would be the most I'd suggest on your hair.