I didn't switch Samantha from puppy to regular food until she was a year old. They spend just about their entire first year growing into their bodies and they need the nutrition found in puppy food.

As for training him... I didn't do paper training. I went outside with her. I'd allow her to play but before she came back inside, I'd point the the ground and say "Go pee-pee!" When she did, I'd praise her like crazy and repeat "Yay!! Samantha went pee-pee!" (or poop-poop, if she did that). The key is lots of repetition of the word and immediate praise once they obey.

Samantha has had ONE accident inside the house since we trained her and that was when her puppy sister came to visit and peed inside the house, so Samantha did too. That was about a month after I got her, and I've had her for 2.5 years.