Edamame are soybean beans, typically grown in Japan and China. These green, ovalish treats have only 5g net carbs per serving - and also provide 4g of fiber.
Edamame are like peas in a pea pod. You don't eat the pod part - you pop the pod open and eat the green beans within. When I buy them in the store I buy them pre-shelled. You get a tray of the nice little beans which you can then sprinkle over a salad to add flavor, color and fiber to it.
The flavor is quite mild, not as sweet as a pea, with a firm texture.
The edamame is of course soy, so people with soy allergies should stay away from it. It has nice nutrition in it - a half cup serving has
10% vitamin C
8% vitamin A
Edamame, being a fresh food item, is perishable. The fresh trays I buy in the produce section of my grocery store are good for about one week. This means, like tomatoes, cucumbers and other salad fixings, you should buy them fresh each week.
You can eat these just as they are, in a bowl, just as you would eat a side dish of peas. You can sprinkle them on top of a salad - I find about an eighth of a cup (i.e. a half a serving) works quite nicely. This gives you only 2.5g of net carbs, plus 2g of fiber too.
Some people salt them heavily and eat them instead of peanuts or chips. That certainly is an option if you're a fan of salty foods - the edamame is certainly FAR better for you than chips are!
If you're a fan of miso soup or egg drop soup, the edamame do perfectly to toss into those as an added healthy item to the mix.
Any sort of stir fry that uses vegetables - broccoli, water chestnuts, etc - can use the edamame as one of the ingredients.
If your local supermarket doesn't stock edamame - either in the fresh produce area or in a frozen / canned style - then try health food stores to see what they offer. There are also websites who will ship you out edamame, you just want to check what their shipping fees are, of course.
Definitely see if you can find a way to add edamame into your mix of healthy foods!