To find the number of back links and PageRank you
will need the Google Toolbar with Advanced Features.
It's a great search tool, it's from Google, it's an essential link
popularity tool, and it's FREE! Get it HERE.
It looks like this:

3. Number of Back Links
By clicking on "Page Info" and
scrolling down to "Backward Links" you can view the vast number of
pages that might link to any particular page. Most sites
only have a few outside backward links to their homepage, and
internal web pages tend not to have any links from other web
sites.

Look at the top right of the page returned and see something like what you see below:

Want to know what page of your web site that Google has
indexed?
Type "allinurl: yourdomain.com" (see below).

*Note, Google doesn't always show every link that points to
your pages. Often if a page that links to you has a Google
PageRank of 4 or less it may not show.
To check your link popularity in Lycos, MSN, and
AltaVista click HERE.
or try this site
NEXT go to GOOGLE
PAGERANK