Adobe Digital Editions (ADE) functions as a go-between to move downloaded books from the library or other source, to your computer, then to an ADE-compatible eReader device. It is fairly analagous to using Media Player or Real Player to tranfer music from your music library to an MP3 player except that you can't move the files manually between folders on you computer as you could with music - you must use the transfer feature in Adobe Digital Editions to resolve format issues. Note: If your device does not show up in your Adobe Digital Editions library as a compatible device, you may still be able to either download the book file directly to your device and/or move and open it using an ADE compliant app like Bluefire Reader.
When you download a book to your computer, you want to save it to the "My Digital Editions" folder that was created in your "My Documents" folder when you installed Adobe Digital Editions (ADE). This will function as your computer-based eBook library folder and it is where Adobe Digital Editions will look for your titles to display in your library of titles in the righthand pane of ADE.
You can use Adobe Digital Editions to read your book on your computer. To transfer it to a reader, plug your reader into a USB port and Adobe Digital Editions will detect your reader and ask you to authorize it to your Adobe ID. Readers used with your copy of Digital Editions will all be tied to that ID. Note: If your device does not show up in your Adobe Digital Editions library as a compatible device, you may still be able to either download the book file directly to your device and/or move and open it using an ADE compliant app like Bluefire Reader.
Once you have synced your device, it will appear in the left pane along with the other pre-created folders provided by ADE.
You can click it to see the titles loaded on it. To move titles to the reader you synced, you can simply drag them from the right half of the screen and drop them into the folder you want.
When you click on the eReader's folder to open it, you should see the title you moved.
If you unplug your reader to use your eBook and can't locate it on the device, look for a folder that Adobe Digital Editions created called "My Digital Editions" - with most readers, ADE will automatically create this folder on your device and place items it has transferred in that folder.