If you are using Omeka.net, see instructions in the Help section of Omeka.net.
1. Upload and install the Social Bookmarking plugin into your plugins folder on the server, see: (Installing a Plugin).
2. Activate this from the Plugins page in your admin panel: /admin=>Settings=>Plugins.
3. Once activated, click Configure. You will see a long page filled with icons of social bookmarking tools and sites. Click the check boxes of as many as you wish. Each icon will appear on the public items/show pages for each item, and allow site visitors to share items on their social networks.
Social Bookmarking and Other Plugins
Keep in mind that if you are activating other plugins that append the items/show page for displaying content those elements may crowd the page's public display.