So as you all know by now, Google has now launched Google+ and the Google +1 Button. Heres how Google+ will affect your website and what Google+ means for your rankings, as of around 3 weeks into the Google+ launch.
First " you need to know that the Google +1 Button and Google Plus are slightly different things that are part of one single system. Its really simple, here's a good analogy: Google Plus = Facebook. Google+1 Button = Facebook Like button.
Google Plus is Googles new Social Network, and the Google +1 Button lets you Like a page.
Add the button to pages where it makes sense for visitors to Like the page. There are many good reasons to have this button, and the early bird gets the worm!
- Sites which have been liked in Google+ have a button visible in organic search results, which will mean that some sites get more traffic not because they are ranking higher, but because they are more visible and attractive
- Google+ likes from people you know affects how Google personalizes your search results " so YES " more likes on your page means you can rank higher for the networks of people who have hit the + button. The Google +1 button IS a new ranking signal.
- Google +1s appears next to your PPC Ads. Notes like Maria and 28 other people +1'd this will appear next to your AdWords ad. For now, this is running only for US advertisers.
- At some (as yet unknown) point in the future, I believe Google will tie Plus into Google Local. There is no timeline on this yet.
If you want to hide the number of people who have +1d your site, you can choose not to show this number on the site when you get the +1 Button code. Click on Advanced Options and unclick include count
Google Plus is Googles new Facebook competitor. Actually, Google Plus looks a lot like Facebook. You see a stream of what other people are looking at, doing, and sharing.
The important thing to know about Google Plus is that people who are using it can add their friends to different Circles. For example, I have a Family Circle, and a Professional Circle, and these circles generally have different people in them. What this means is that Google knows who you know, and how you know them.
Note that Google+ is not accepting business profiles yet, and businesses who set up a profile may be shut down. Google is working on a beta right now to allow businesses to set up profiles, but if you do it at this time, without invitation to the beta, your account might be shut down.
Difference Between Google Plus and Google Reader
Here's an interesting gotcha you should be aware of:
This is the new Google Plus button. When visitors click this button, it is a thumbs up for this page.
This is the old Google subscribe to RSS button. This is NOT Google Plus " some people will mix this up. 
You can have both of these buttons on one page, since they have completely different purposes. The Google+ button likes the page, and the longer Google button subscribes people to the sites RSS feed. Im certain they will be changing the Google RSS feed button in future to avoid confusion.
How to Get Reports on Google Plus
Google Webmaster Tools now has a reporting area where you can see Google +1 Button activity on your site. In here, you can find out which pages are being Liked?... Plussed? +1D? No official jargon on what to call this yet!
So to sum up the important points of Google+ so far briefly:
- Google Plus = Facebook, and Google +1 Button = Facebooks Like button
- YES " you should put the button on your site on pages appropriate for people to Like the page, especially the homepage
- YES " Google+ is a new ranking signal
- YES " Google+ will show up next to AdWords PPC ads in the USA
- NO " You DONT need an invitation to use the Google +1 Button " just put it on your site
- NO " the old subscribe to RSS Google button is NOT Google+
- YES " you can get a report on Google Plus on your website in Google Webmaster Central