I wonder if I bought a book out of Barnes and Noble Web site or Web site if Sony would be able to read on my Kindle? Anyone know?

I ask my parents for a Kindle for Christmas to think, but if normal eBook as much as the books (such as cost, about $ 10) I do not think I would also be able ebooks wollen.Ich pirate?

Moreover, there is a way to determine if a particular book is available for the Kindle before I buy one for Kindle? Thank you!