If this is what you said when you received a Barnes and Noble Nook for Christmas, then this is the post for you! First, what is a Nook? It is a device mainly used to read eBooks. For all of the details about the Nook, go to the Barnes and Noble website.
So now you’re probably wondering, how do I get eBooks on this thing? Luckily it is not too hard to do. The library’s OverDrive catalog has a large variety of fiction and non-fiction reads for both adults and children.
For more information about how to use OverDrive, the help page is extremely useful.
(Please note, this information is for the original Nook, not the Nook color. This post is only about the Nook because the author uses one; other devices for reading eBooks are also awesome to use with OverDrive!)

Thanks
Do we need an adobe activation of nook to transfer files?
I just got a Kindle, can I download e-books the same way?
EPUB For kindle
No on the Kindle
Unfortunately, because the Kindle can't read Adobe EPUB or PDF files, you won't be able to download books from Overdrive. Amazon does have some free eBooks you can download to your device, most of them are classics or limited time promotional books. There is also a list of links to other ways to access free books. Hope this helps!
This is similar for the Sony Readers
Thank you!
Thank you for the tips on the Sony Reader! I think it's awesome you can just download the books straight to the device. I ended up getting a Nook Color a few weeks ago and even though it has many more features than the original Nook, I still have to sync it with my computer at home and transfer the file/book. It's still a great device to have. Thanks again!
Sony Readers download to computers too
Notes from a Nook
I got a Color Nook for Christmas -- followed the instructions above which seem straight forward and downloaded an eBook. If you haven't done an Overdrive download before it may be difficult. Be patient. Read over the instructions several times and print them out or otherwise keep them handy when you're starting to download. Overdrive has some good tutorials so you may want to look at them first.