We use a number of different treats. Anything from biscuits, kibble, hot dogs and we got a bag of treats that our trainer uses, all natural etc. I can't remember what it's called at the moment. But he loves them. Honestly, they look like rabbit turds...
smell good though.
There are some home grown videos of Michael ellis on you tube that shows him giving training classes. I like his philosophy on a number of different things.
All our training has been positive until recently. He is 13 weeks and can be a touch stubborn at times. We are only using a few leash corrections but we really don't have to do that much. Ours is very treat driven.
With a dog that is on the soft side, I would only use positive reinforcement. Especially at the age of your pup. Our last Shepherd, if I raised my voice at all she would fall to pieces. I had to be very careful about my tone of voice. My wife is also big on facial expressions.
Listen to Danielle and David Winners. By far some of the most experienced.