The Heritage Foundation has put its Guide to the Constitution online, and it makes for lots of interesting reading. The interpretation is originalist, although several of the contributors make an effort to be fair to other interpretations, but even for those who aren't originalists themselves there's a sense in which originalist interpretations are the most interesting reading, because they necessarily get into the history of the thing and show what the original point was. I was especially interested in seeing how the essay on the 27th Amendment was, and the author does a good job in brief space of explaining what is the most interesting of the Amendments, considered simply as amendments. The 27th, if you'll recall, was one of the original amendments proposed for the Bill of Rights, but didn't pass; it would have established a limitation on Congressional compensation (if they vote themselves a pay raise, they have to wait until after the next election to get it). Here and there another state would ratify it, but never enough to do anything (as the number of states increased, the number of states needed to ratify it increased). Two hundred years later, a college student started a ratification campaign after researching it for a term paper, and ten years after that Michigan became the 38th state to ratify it, thus finally making the proposed amendment meet the Constitutional requirement and unexpectedly smacking Congress upside the head. Because the ratification process took so long, there was some question of whether it was really a valid ratification process, but Congress, weighing the situation and realizing that they could not politically win a fight over whether to accept an amendment restricting their ability to compensate themselves, caved and recognized it. Heartening, really, despite the fact that the amendment isn't exactly earth-shattering; it shows that, though the leash may be miles and miles long, there's still a choke collar around Congress's neck, and the other end is still in the grip of the American people.
In any case, the website makes for some interesting reading if you have the time.
