Verify PR

Read any article about SEO and you will see high on the list of things you should be doing is linking but what does this mean?
In this instance linking refers to getting other websites to add a link on there site referring people to your site, there are several ways to do this you can buy a link from a site that has complimentary content to your site, you can swap links with other sites and you can make your site interesting enough that other webmasters refer to it as an authority site.

Is main page linking enough?

If you get sufficient interest and links to your index page you will soon have a page rank of 2 or 3 but to get a ranking on other pages you will need to consider deep linking which involves having both navigational links from your index page to your secondry page and external links from other sites

unfortunatly just having a link from another site is not enought to give you a ranking because the search engines look at the rank of the page with an outgoing link and then devide the page rank by the number of links so if your link is placed on a page rank 2 page with 20 other links the vote that that site gives to your page is a total of 0.1 pagerank. As you can see you would need at least 10 such links to raise your page by just 1 rank even if this was all the search engines were looking for.

If your index page have a rank of 3 you can transfer some of that rank to your secondary pages but remember that the more links off of your indexx page (or any page with a ranking) the less each link is valued.