Gearheads of War

Hey guys just a quick question. does anyone know where I can go to read the Halo books online for free or at least a good break down of them? I am interested in reading them but I really dont want to pay for them. I know there are tons of legal resources to read free ebooks but I havent been able to find one with any Halo books.

I read the wiki's on all of them but was hoping to find something more in depth somewhere for free.

Thanks for any help you can give guys.