Originally Posted by Gunnerp245
Use connect to folder in calibre and transfer via USB. Search out userr DoctorOhh in calibre forum.
I haven't tried the Connect to Folder feature via MTP. Of course you could use Connect to folder to any local folder on your computer then easily transfer the books via the file manager. That said, calibre will connect directly to the device and you can use the Send to device feature just like any other ereader, no app required.
Personally I spent the Big Bucks ($2.99) and purchased the Calibre Companion
app. This App is so much better then either of the two methods I just described.