The quick links list in the My Portal menu at the top right of the page is a way for you to quickly access the content that you need most frequently.
As you visit content around the site, you will see bookmark buttons. When you use one of these buttons to add a bookmark, that piece of content will appear in your bookmarks list, which you can see either in the Subscriptions/Bookmarks page under your user profile, or you can get there directly by clicking the "manage" link next to the quick links list.
The Quick Links list will always show you your five most frequently visited bookmarks, i.e. those which you really do find most useful. If you haven't bookmarked five pieces of content, then this list will populate with the content that you visit most frequently.
Yellow star icons in the quick links list indicate content that you have bookmarked, while greyed out empty stars indicate content which you have not bookmarked, but do visit frequently.