Bookmarks are an extremely effective way to differentiate learning, keep all students active, and
provide parents with quality help sites to involve them in the teaching process.  Simply sign up for one of the free services, and place all the Internet sites of value to your lesson on the bookmark site. Students can then access this site from anywhere in the world and use the data to help with the lesson, do online tests, get homework help, or even translate material.

Get a bookmark site for your class and, in it, include state standards and resources on issues to educate parents how to help their children.  Place current events on the bookmark site, as well as sites that show how to take notes, cite bibliographic data, and find videos related to your classroom lessons.

Here are some bookmark sites you can explore and sign up for without charge.

emailaddresses.com Free Bookmark Managers

Free Bookmark Managers 

Free e-mail Guide Free Bookmark Managers 
Nice summary of bookmark sites

Google Bookmarks

Google Directory of Bookmark Managers (social)
Please note that social bookmarks may not meet your classroom criteria.

The Loose Wire Blog 
See this blog about sophisticated bookmark managers that can be used in a variety of ways.

Murl 
Read about its limits first.
 
PC World -- The Web’s Most Useful Sites 

Yahoo Bookmarks