What kind of Samsung device?
If it is a dedicated eReader it should show up in Digital Editions (ADE) when plugged in by USB.
ADE 2.0- has compatibility issues with some eReaders; try the older version, see note at bottom.
If it is a tablet, you need DRM capable eReader software; I suggest Bluefire.
Then copy the books using a file manager (eg Windows Explorer, Mac Finder). to the mounted drive
There are lots of bugs in ADE2.0 (and 2.0.1). Try replacing ADE2.0 with the older but more reliable v1.7.2.
(You can have them both installed at once if you like.)
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172