Many webmasters spend a lot of time optimizing their home page only. They do this by optimizing onpage factors like H1 tags, title, keyword density, alt tags, etc, and offpage factors like the number and quality of inward links from other sites. That's fine and is something you should definitely do, but you should also take some time to optimize all of your inner web pages as well.
This is because if you can get a good pagerank for all of your inner pages, as well as your home page, it increases the chances of these pages being ranked highly in the search engines for their chosen keywords, and increases the number of visitors you could get.
So how do you achieve this? Well firstly I recommend that all of your main web pages are just one click away from your home page. You should have a well-structured navigation menu on your home page. Each link within the menu should be an anchor text link containing your main keyword(s). For example, let's say you had an inner page about hair loss. Now you may have done keyword research and found the term "hair loss" to be too competitive, so let's say you have decided to optimize your web page for the less competitive term "male hair loss". In this example, your link from the navigation menu should be "male hair loss" rather than "hair loss".
You can dramatically enhance this interlinking structure and boost the pagerank of your inner web pages further by including this navigation menu on all of your inner web pages. This means that all of your main inner web pages are always just one click away and will dramatically boost the number of inward links that each page has. This can be very powerful because with higher pagerank and more links comes higher search engine rankings, but surprisingly is something that many so-called SEO experts fail to recognise.
Another way of achieving this effect if you do not want to include a navigation menu on every page is by including a link tree on every one of your inner pages. These are those links that you often find at the bottom of pages, and are again a very good way of interlinking your web pages. As before, be sure to include your main keyword(s) within each link.
I personally include a left-hand navigation menu on all of my websites, as well as a link tree at the bottom of each web page. This ensures not only that each page of each site has the maximum number of internal inward links, which boosts my pagerank and search engine rankings, but also ensures that the visitors to the site are always just one click away from each main page of the site. This is important if they enter at one of your inner pages, because often they will then want to navigate to the home page.
To conclude, to rank highly in the search engines, you should focus on on-page optimization, and more so off-page optimization. Just as every inward link to your site from another website acts as a vote for your site, and boosts your pagerank and search engine rankings, a link from another page within your site also acts as a vote and will also have a positive effect on your ranking. A good interlinking structure within your site will ensure that every page is fully optimized and has the optimum number of links from your other pages allowing you to rank higher for all of your inner pages as well as your home page.