Civics hasn't really been taught in most schools for a long time, yet study after study demonstrates a higher participation in our system of government and better understanding of how it works. I've used the "We the People" program for over 8 years now, it works. Over the past 3 years, the Center for Civic Ed has revised the texts, now they've got a companion site for the HS level. I'm going to use it this year for my middle schoolers, their reading level is ok and with some minor modifications I think they enjoy being able to use technology that can be incorporated with it.

http://www.civiced.org/wtpcompanion/hs/

If you'd like to get some idea. If it looks like something you'd like to use, go to the http://www.civiced.org site and look up your state rep, if available they'll send you the texts, teacher edition, and supplementals at no cost.