The Link System package provides a cool way for you to manage categories of links across your site.
It allows your users to suggest their own links (with optional captcha and email validation), which you can approve from within the dashboard. You can choose to be notified by email when a user suggests a link that needs your approval. Links can optionally display thumbnails. You can also set the number of links per page, and can sort by newest, oldest, or title. If you've got a lot of links, you can even display a search field.
Want to test it out? Check out the Link System demo »
Note: If you're looking for a more basic way to manage a list of links, then check out the Link List block.
Project Page: http://concrete5packages.com/toolbox/link-system