Social media sites have revolutionized the way people communicate - and it ain't all good.
The first site I joined was Facebook. It took a while to figure out how to protect my privacy (posts, photos, phone numbers..) but it's really improved. FB allows me to keep up with the lives of distant family and friends, which sadly is the only news I ever seem to get from them.
After several years of using Facebook, I'm beginning to resent it. It has basically replaced the Christmas letters, occasional phone calls and visits. Is that a good thing? I heard about a child's graduation but I had to ask if it was high school (it was but the photo showed a young woman who looked about 21). A nephew got married and I didn't even know until I saw the photos!
Although FB allowed me to "friend" people I used to go to school with, they usually post "what we did this weekend" or repost their kids stuff. More people are learning how to create sub-groups for "family", since I see fewer of these.
My real friends are not active on Facebook at all, but I stay because every once in a while it leads to actually seeing or talking to people. I met with a school friend recently who was visiting my area (from the other end of Canada) and it was more fun than all the online posts put together. We reminisced about all sorts of things and discovered why we had always like each other. I'm even considering making the trip for the class reunion next year - of course they are going to organize it on a Facebook group. It seems that people new to the Internet learn how to use email, how to search in a web browser, and then join Facebook. In that order. (I recently helped a couple with their new chromebook, which is basically a laptop that only runs a web browser - and thats all they need!)
Facebook also offers "Pages" which are being created by businesses at a fast rate. Just remember that if you hit the "like" button on a Page, their posts will appears in your news feed (aka timeline), mixed in with friend news. That's also the reason businesses offer prizes or coupons if you "like" their page - they want their "ads" in your news feed! It costs them nothing at all. Makes more sense to "like" organizations you belong to - you want their news.
Twitter is another thing altogether. On my personal account @patdrummond I "follow" people who share interesting information, often people I've never met. I also have two accounts that are used to post news for websites (@BoatinginCanada @ManotickDir). I can't keep up with them, but I try because it's just expected.
Google Plus (G+) is similar to Twitter but without the 160-character limit. Images are inline so it has more multi-media. There's also more discussion just because it's easier (and longer). It's disadvantage is that I use Hootsuite software for my social accounts and it doesn't support G+ yet -- only G+ Pages.
LinkedIn is a business networking service. I have an account but am not active since I'm retired except for my websites. If you're in business, a professional or provide services, you have to use this service to network. Joined a business breakfast club is so last year!
These are the most popuar social sites and they're all free. Go ahead and jump in with both feet. You will find an amazing world to sample, new friends to make (maybe) and even reconnect with old friends. But as for the benefit to Real Life, I'm not so sure.