Google Pagerank

Perhaps you have heard of Google Pagerank. Its a way measuring how popular/important a site is.
When you first publish your site you will have a pagerank of 0, max is 10.
If you want to get a higher pagerank you will have to have other sites link to your site. But the sites that are linking to you should be sites with a high pagerank. Also you want "good" sites to link to yours, sites that Google think are good sites.