Pentagram... School project

Hey, I'm having a project on the school about the pentagram.
And I was wondering if anyone has any good sites or link to sites about the pentagram?

I'm looking for info about history, its use in secret societies, religions...
And some info regarding the Washington DC. pentagram or other similar places with pentagram connctions.

I can't help you much but I had seen this thread the other day.
Inverted pentagrams

I'm sure there is useful information in there for you.