Hey are there actual super natural books I can read. Also how about items such as t-shirts posters & such?

Well, they do have alot of merchandice... but yes, there are actually books you can read, the novels that is. However they can sometimes be a challenge to find...
They have t-shirts, posters, mugs, dogtags and even calenders! Here's a great site to use:
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There are about 5 or 6 Supernatural novels out. I've read two: Witch's Canyon and Nevermore; they're ok. What's really cool are the comic books which are a prequel to the show. If that's your sort of thing I'd definitely check those out.

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^There is also a 'Supernatural Book of Monsters, Spirits, Demons, and Ghouls' Here's a pretty cool description:
>>A one-of-a-kind compilation of all of Sam and Dean's demon-busting knowledge, The Supernatural Book of Monsters, Spirits, Demons, and Ghouls contains illustrations and detailed descriptions that catalogue the more than two dozen otherworldly enemies that most people believe exist only in folklore, superstition, and nightmares:vampires, ghosts, revenants, reapers, and even bloody clowns. You'll find within these pages Sam and Dean's notes, observations..<<

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^Another cool book is John Winchester's Journal.
>>Part prequel, part resource guide, John Winchester's Journal finally gives fans the ultimate companion book for Supernatural. It's all here: the exorcism Sam and Dean used in "Phantom Traveler," John's notes on everything from shape-shifters to Samuel Colt, Dean's first hunt, Sam's peewee soccer team . . . and John's single-minded pursuit of a growing and deadly evil.<<

Those two I think are the best for hardcore fans and fans who are curious to see just how much knowledge the Winchesters have.

yes they do. you can go on link and look up supernatural and they have a lot of things that's were i got mine books.

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This sells supernatural magizines, books, t-shirts, jewellary, photos, comics, dogtags, busts and games