The web site should contain some interesting articles, a description of what is available on the site and some helpful links to other information of interest. (articlesfactory.com)
For example, if you're marketing to parents of small children you might advertise on parenting websites and on more generalized sites that have sections with information of interest to parents. (entrepreneur.com)
Target by grade level and / or geographic area, and get the contact information of interested parents. (familiesempowered.org)