Kobo

Kobo (PC)
To add ePUB or PDF books to your eReader using a Windows computer:
Connect your eReader to your computer using the USB cable. Your eReader will prompt you to either keep reading or manage your library. You can use your computer or the Desktop Application to add books and manage your eReader.
Using the Navigation Pad, select "Manage Library". Windows should detect that you connected a new device.
When prompted for an action, select ‘Open folder to view files.’ A window should open, showing the contents of your eReader.
In another Explorer window, navigate to where you stored the eBooks you want to move to your eReader.
Drag and drop your eBooks into the eReader window. You can now disconnect your eReader and read your new books. Turn on your eReader and find your new ebooks. They will be in the "ebooks" area.
Kobo (Mac)
To add ePUB or PDF books to your eReader using a Mac computer:
Connect your eReader to your computer using the USB cable. Your eReader will prompt you to either keep reading or manage your library. You can use your computer or the Desktop Application to add books and manage your eReader.
Using the Navigation Pad, select "Manage Library".
On your computer, open your Finder application.
Select KOBO eReader from your list of devices. Finder should display the contents of your eReader.
In another Finder window, navigate to where you stored the eBooks you want to transfer to your eReader.
Drag and drop your eBooks into the eReader window. You can now disconnect your eReader and read your new books. Turn on your eReader and find your new ebooks. They will be in the "ebooks" area.