Is he AKC registered with a pedigree? If not, then don't breed him.
It's easy to say your dog looks perfect, when you're biased. I have a Pom, and even though I know he doesn't fit the standard, I still think he's perfect. He's a wonderful dog. Could probably make wonderful puppies. However, I know nothing of his background, and he has horrible conformation for a Pom.
If you want, take some photos of him stacked and put him in the critique section. A lot of people can tell a puppy's potential, as far as conformation goes, with a few good pics.
Here's a video on how to stack a GSD. Pretty much the same thing with a pup. (I wouldn't expect for him to be this cooperative when you try it, if you've never done it before).
Look at the flowchart on this page and follow it.
"Should I breed my dog?" Flowchart
The only reason anyone should ever breed their dog is to try and better the breed as a whole.
As far as I know, there's no 'set' standard for whelping pups. There are a lot of people on here who are knowledgeable in that area, but you can never EXPECT anything to go as planned. Things can go wrong and you might lose the mom and/or her puppies, rush her in for an emergency c-section, she may reject the puppies, forcing you to hand raise them, etc. etc.
Breeding is not something to be considered lightly.