new to site

Click on the Groups tab , Find the group you wish to join, and click the "Join Group" button! Best of luck and welcome! (:

Sometimes, with an open group, you can just simply start adding comments on feeds to be included in the group.

And in some others you must request to join the group. Or even be invited into them. Depending on the group you want to join. But as NicNac said, open the group you want to join, and search for the "Join group" button

As others said...you click on the group and under its description there is a blue button saying "Join Group". You click on it and that's it. You get 25 points for joining a group and -25 points for leaving a group. That's just an additional information. The main point here is helping one another as we can :) Enjoy.