Charlie_Blair - 8:54 am on May 29, 2013 (gmt 0)
No it's not a good idea to post on every forum and every category, you need to post on related blogs and forums. To build links properly, you need to create value for the person reading to forum or blog. You need to stay on topic on the right forums or on the the right blog. For example, your education website, could be linked to a mommy blogger, by commenting on a post about educating children etc.
Hope this helps