Teachers" Union to Open Lesson-Sharing Web Site Teachers seeking lesson plans on anything from fractions and multiplication tables to Shakespeare or the Civil War can take to the Internet for a boundless array of work sheets, reading lists and classroom tips, available free or for a fee. Now the American Federation of Teachers is forming a partnership with TSL Education, the British publisher of the weekly Times Educational Supplement, to create a Web site where teachers can share curriculum materials with one another. In a somewhat belated entry to a market overflowing with online educational advice, the teachers" union believes that its site, to be called sharemylesson.com, will become a go-to destination because of the union's imprimatur. "We are taking the trust that people have about us and transforming it to trust about the site itself," said Randi Weingarten, the union president. Teachers will be able to upload anything from a simple work sheet to an entire semester unit, as well as PowerPoint presentations and videos. Other teachers can then rate the resources, and the site's algorithm will rank the most popular and well-reviewed lessons. At a time when public school teachers face cuts in financing and are being asked to carry out new national curriculum standards in English and math, Ms. Weingarten said teachers were desperate for specific lesson plans that had been tested by others in the classroom. "It is very easy for someone on high to say, "These are the standards that you will be teaching to," " she said. But where are the resources, the tools to actually make these things sing in their classroom? Sharemylesson.com is modeled on tesconnect.com, a Web site created by TSL in Britain. TSL, which generates its revenues by selling teacher recruitment ads in its Times Educational Supplement and Times Higher Education magazines, started the Web site four years ago and has since amassed two million registered users in 197 countries. Both TSL and the union have invested cash and staff time worth about $10 million combined in the American site. Louise Rogers, TSL's chief executive, said that although the company would eventually want to make money from sharemylesson.com, teachers would always have free access to the material created by other teachers, as well as content from other partners including Sesame Workshop; WETA, the public television and radio station in Washington; and Student Achievement Partners, one of the architects of the common core standards that 45 states have agreed to adopt. "If you throw the wrong commercial model at it too early, you will kill it," Ms. Rogers said. If they are here to share user-generated content, you can't turn that into a marketplace and think you can get away with it. Anyone who types "lesson plans" into Google will come up with millions of hits, with a variety of online resources at sites like Edutopia.org, Thinkfinity.org, Teachingchannel.org, Readwritethink.org and Betterlesson.com. Some offer free material, while others, like Weareteachers.com and Teacherspayteachers.com, are sites where teachers sell lesson plans. Textbook publishers and other educational companies also operate Web sites where teachers can buy material. Amy Spies, one of the teachers recruited to help vet the content uploaded to sharemylesson.com, said she often found the volume of education tips online overwhelming. "My hope is," said Ms. Spies, who teaches gifted students in the fourth grade in Port Orange, Fla., "that this will be a one-stop-shopping area which is free for teachers, where you don't have to join or use a trial membership where you forget to cancel and all of a sudden you are paying for it." While many teachers relish sharing lesson plans, some say they might also hesitate to simply give away materials they have spent years fine-tuning. Laura Bradley, who teaches eighth-grade English in Petaluma, Calif., and participates in several online communities, said she was recently asked to post an entire unit on the Web. "It was the first time I paused and thought, "I have spent 10 years developing this unit, tweaking documents," and I wondered, "Do I just stick it all up there?" " she said. Ms. Bradley added that the union stamp would not necessarily attract her to the site. But she said that if she experimented with it and discovered that the content worked in her classroom, "then it would becomes one of the sites in my bookmarks."