Congratulations on your new addition. It's great that you're doing research...unfortunately you've ended up with the wrong mentors.
Switch Cesar Millan, the Monks of New Skete and Jan Fennel with Sophia Yin, Ian Dunbar and Jean Donaldson. Millan is not respected whatsoever by the behaviourist community; the Monks do have some good ideas but lots and lots of dated and old school methods (it was the Monks who came up with the horrendous and now completely debunked Alpha Roll); Jan Fennell has some good stuff but is very much a "you're not alpha, that's why you have problems" person, promoting the alpha training methods that all behaviourists advise against.
Sophia Yin has a ton of good videos. She is considered one of North America's top dog trainers and veterinary behaviourists
Ian Dunbar has written a lot and has a lot of free info online, including specifically teaching to walk on lead
You'll see that the experts all recommend simply stopping when a dog starts pulling, til he stops and checks in with you. I do this and it does work - some dogs are slower to pick it up, but the thing that may make this fail is not the method or the dog but the handler. Some people want instant results. Instant results usually come only with aversion-based methods which virtually all behaviourists adamantly advise against.
There is one TV show that uses an actual qualified behaviourist, not a dog walker or self-certified "expert" (very easy to read up on the methods some of these guys use - google their names with "abuse" and see all the videos and stories). Victoria Stillwell has a great clip below discussing the two schools of thought re dog training, and there are a ton of other good clips there as well.
There are great books out there, and while I realize you're asking about pulling onlead, the biggest issue is getting in the right place with your dog, and being able to communicate with him. So really the best place to tackle this is in basic training and obedience. Educating your puppy to want to listen to you (as opposed to instilling in him fear of you). When you have that relationship, each individual issue (pulling, mouthing etc) is a minor technical issue as opposed to huge deals that you hear from so many - it's not that the dog is just pulling onlead - it's that the dog has absolutely no respect, won't listen to anything, barges past anyone, is out of control, etc. In those cases, pulling onlead is the least of your problems.
Here is what the experts in animal behaviour think about Cesar Millan and other alpha training methods.
And a great read to really open your eyes about people and dogs, by Jean Donaldson: