First of all, wash your beans so that they are clean and free from dirt, bits etc.
Then, bring to the boil at least 6 litres of water per 500gms of beans, preferably in a large pot with a steamer/basket type arrangement. The water must be at least half way up the basket, so that all the beans are submerged when placed in the water.
Before the water has come to the boil, make sure you have another bowl of cold water to place the beans in after blanching. The beans have to be cooled rapidly to stop the cooking process. That way, you can preserve the freshness without cooking them all the way through.
The beans will cool down. If you are making another batch, make sure you change the not so cold water bowl for fresh cold water, because you are still attempting to cool the beans down as quickly as possible. Once cool to touch (about 1 minute) then strain and place in a freezer bag.
If you are freezing other types of vegetables, the blanching time will vary with the size or weight of the produce. Just google “how to blanch vegetables for freezing” and you should find the right time for whatever you want to freeze.
I managed to get four meals out of my 1.9 kg of broad beans. We ate some tonight with our roast which were very tasty and I froze the other three portions. I hope this has been educational.