I just had an interview.how do you think it went?

I answered all the questions pretty good, and there were no wierd moments or anything. She told me about training and their benefits package and when I asked her when I would here from her she said probably within a week. Do you think this is a good sign because she told me about the hours, benefits, and training, or do they tell that to everyone? What should I do next? I heard I should send a thank you letter maybe. How does this work?