My husband got Pixie, my Chihuahua, for me when she was 6 weeks old. At that time our house was not yet completed and training a new young pup was no easy task. My best advise is consistancy. I would get up with her 3 times a night to feed her, water her, and take her outside. When we were at work she stayed in a crate. Our being consistant quickly trained her and she has always respected our home and her own area. (This also prepared us for children.)