Of course you can. Most of iBooks support ePub.For this [iPubsoft ePub Creator][1] is helpful for making ePub files from HTML, MOBI, TXT, Word, PDF, etc.with fast speed and superb quality. Then you ...
I am afraid that iBook files can be read only on an iOS device. The future is uncertain regarding their usability on Windows PCs.
In iTunes, click on your device and "Transfer purchases". It copies the books to your local hard disk. The rest depends on OS you use.
iBooks do not allow us to read them on pc, because they are protected and pc can not relieve the limitation by itself. But there is a method how to do that. Surf the web.
