When I potty train I use a grass pad (I prefer this) and puppy pads. Never should a puppy be hit, refused food or have their nose rubbed in their feces as punishment. I use kisses, praise, treats and tell them "Good boy/girl". Puppies are very smart and eager to learn and please you.
A few great links to help with potty training:
www.perfectpaws.com
www.humanesociety.org/
www.aspca.org
Links to help with puppy training problems:
www.perfectpaws.com
www.aspca.org