google only shows you a small sample of the total number of links pointing to your site...Yahoo shows all that it has picked up so far
Yahoo site explorer https://siteexplorer.search.yahoo.com/mysites is quite jazzy and lets you see Yahoo's view of the inlinks to your homepage and whole site, excluding links that come from your site if you want etc etc etc. If you want to get down and dirty, use Aaron Walls http://tools.seobook.com/backlink-analyzer/ Backlink Anayzer which tells you all the stuff you want to know as well as the stuff you don't.