In Pinetree Garden Seeds' catalog I see two type of soy beans. Envy is an Edamame Type soy bean. "...produce a heavy yield of bright green beans which can be either shelled or dried."
Then there is Vinton. "A yellow seeded type, Vinton is wonderful for tofu production and also great used fresh like a shell bean."
So, both type can be eaten fresh or dried. But I would assume that Edamame type is more tender and easier to cook. Since Edamame type is bred to be eaten fresh. I usually cook soy bean with pod in water until it is tender, then add salt, peper or Chinese "five-spice-powder", boil for a few more minutes. It is very important to add salt after the beans are tender, otherwise it is remains crunchy. It would help if you cut the end of the pod so that salty water can get into the pod easier. Then drain and server as snack. When you eat it, either peel or squeeze the beans out.

This link talks about all kinds of beens. You may find it helpful. http://the-vegetable-site.com/VEGGIES/bean.shtml

I've seen the "Lucky Lion" variety in a number of places advertising edamame-type soybeans.

I'm hoping to grow edamame this year as well; looks like we're in the same area.

Here is a link that might be useful: Edamame at Evergreen Seeds

Most soybeans in the US are grown for dry beans and don't taste good fresh. Johnny's Selected Seeds sells a wonderful green variety called Butterbeans. I've grown them several times and they're delicious.

Here is a link that might be useful: Johnny's green soybeans