Currently Being ModeratedDec 1, 2012 5:26 AM (in response to ilovephotos)
You can't install the Apple app iBooks for reading ebooks on a Macbook Air -- it is only for iPads/iPhones/iPods.
So what did you actually install? If it was iBooks Author, that doesn't read ebooks, it creates them.
Books from the iBookstore normally have to be read on an iOS device. Where exactly did you get yours and what is the title?