Your page should load in less than 5 seconds because search engines will penalise sites that have longer loading times, or are frequently unavailable.
If you page is taking longer than 5 seconds to load, you should strongly consider optimizing the HTML, seperating it's content into sub-pages or upgrading your host.
High Performance SEO Requires Fast Load Times - searchenginewatch.com Discussion on webmasterworld.com Myth busting: delays in page loading - mattcutts.com