The LinkedIn Groups feature is always rated very highly when I do my annual LinkedIn user survey, and rightly so.  

business card exchange 
There are so many benefits to finding the right groups and then putting together a strategy for your involvement in the group and with the individual members.
One of the most important strategies is to find and reach out to people you are not already connected to. It's a virtual way of doing what you typically do at industry conventions and networking events, where you randomly meet people or target the people you're most interested in meeting. 
Here are the simple steps to find the right folks in your LinkedIn groups:
1.  Click the group logo of the group you're interested in searching. You can do this from the bottom of your profile or by going to the top toolbar and clicking Interests>Groups.
2.  Click the number of members 
on the top right, and then a search box will appear.
3.  Type in the appropriate keywords following
4.  Click the Search button, and you will then see a list of all the people that meet your search criteria.
Then, right from that list of search results, either send a direct message by clicking Send message or, better yet, ask them to connect by crafting a five-star connection invitation
This is the virtual version of strategically  "bumping into them" at the convention or networking event and beginning a relationship with them.
If you need help finding the LinkedIn groups that are best for you, download my worksheet LinkedIn Groups: Ca$h in on This Powerful Tool, which is part of my free LinkedIn Essentials Toolkit. Click here for your free kit.