They'll have it wrapped around their necks like a big necklace. They are not the easiest birds to train to do tricks, but they have enough cute antics of their own to make it worth working with them. One trick they will pick up very quickly is the ability to 'step up'. This is the first command you should teach your bird. As far as speaking ability, I've personally never seen a female cockatiel speak, but have heard some folks say theirs have.
Most male cockatiels have the potential to learn to speak.
The cockatiel's voice isn't the easiest to understand, it's sort of squeeky and scratchy. Although their voices are not nearly as clear as amazons, they can attain about as large a vocabulary. Tiels are generally pretty quiet birds, especially when compared to most of the larger parrots. Your tiel will require time out of the cage. How much time depends on the individual bird.