There`s an awful lot of info on cockatiels out there, so if you have any specific questions be sure to ask away.
If you haven`t picked one up already, it`s a good idea to get and read at least one quality cockatiel/parrot book. There are a lot of bad ones, so be sure to buy ones that were written recently or that were specifically recommended to you.
I recommend Cockatiels for Dummies, Birds for Dummies and/or the Companion Parrot Handbook. The last one focuses more on behavior, and the first two are more general guides to choosing and keeping a bird.
Be sure your bird is on a healthy diet, and if she isn`t you`ll have to make the diet change gradual. A healthy diet should have a mix of pellets, veggies and seeds. If it`s healthy for you, it`s healthy for your birds. Veggies that`re vibrantly colored tend to have the most nutrients. Please don`t give your bird avacado, onion, mushrooms, rhubarb, caffine or alcohol, or salty/greasy/sweet foods.
For pellets, choose a brand that doesn`t have artificial dyes in it, as the colored pellets can contribute to feather picking, feather discoloration, or even cancer. I recommend Roudybush, Harrisons, Hagens or Zupreem Natural.
If you haven`t yet, I recommend getting your bird into an avian vet for a well-bird exam. It can catch problems before they become life-threatening, as well as establish a relationship with the vet and a baseline for the bird. When I got my first cockatiel his well-bird exam saved his life. The vet caught an infection early and it was easily corrected.
If you have any questions, don`t hesitate to ask. The cockatiel board tends to be more active than the beginners board, though.
Welcome! And goodluck with your little girl. Cockatiels are a lot of fun!