How I Use It
ThirteenEd Online is in the process of moving to a new site. Some of the content on ThirteenEd Online is a bit old while the new site, WNET.org/Education seems to have a broader education focus, not just lesson plans and resources, and hasn't fully migrated all the content over. In addition, most of the lesson-specific content seems to have been moved to pbslearningmedia.org.
At this point I'm honestly not sure how I will use it. Since the move from the old EdOnline site to the new portal and PBSLearningMedia site it seems like there will be a bit of a new learning curve on navigating the new pages.
ThirteenEd Online is in the process of moving to a new site. PBS has moved the education focused content over to http://www.wnet.org/education/. That being said, http://www.thirteen.org/edonline/index.html still does have a few resources that don't seem to be on the new site, such as a collection of lesson plans for the upper grades (6-12) dealing with financial math as part of a Citi Group grant.
The new site, WNET.org/Education seems to be acting more as a portal to app/game/series specific pages. PBSLearningMedia.org appears to be where the majority of resources such as unit and lesson plans has been moved to.
Overall it looks like PBS still has a wealth of resources, they are just moving things around and re-branding their educational content. I would recommend teachers focus more on http://www.pbslearningmedia.org/ as opposed to thirteen.org/edonline.