I can see by my "circle count" that there are a lot of new people signing up today. In the early days of G+ (just 90 days ago) there was a culture of sharing tips, tricks, guides, etc. I gathered together a few for the new users who just joined. Be a pal and share them with your new friends on G+ :-)
A complete guide to Google+: http://on.mash.to/qjq3EU
A G+ guide created collaboratively by users in Google Docs: http://bit.ly/n8uGoV
Big info graphic with tips & tricks: http://bit.ly/oA90Zt
Smaller "cheat sheet" graphic: http://on.mash.to/pJjNjF
Visual guide if you hate to read: http://bit.ly/nkFjkj
Btw, keep in mind that G+ is not like Facebook, which is what a lot of people seem to think based on the press they've read. G+ is something different, maybe more like a combination of Twitter & Facebook. You can "circle" people and just see what they post, like following on Twitter, but you can also use your circles to post to select groups of people (more like Facebook - your smaller group of friends).
If you find your friends aren't here yet, the best thing to do is find interesting people to circle-- the main link I've shared below is one of the nicer sites to see a list of suggested users you can circle (and of course, G+ has its own list of suggested users when you sign up). Enjoy :)