Check out this post for litter training. it is the system I use and I'm a huge fan of it.
http://www.yorkietalk.com/forums/tra...while-ago.html
We've lived in apartments and just can't get him out fast enough, so he uses this, if you start right away it's actually not hard at all to get them used to it. and it's cheaper than pittle pads, and smells less than the potty patch.