The first step is to visit OverDrive on your computer: http://sanantonio.lib.overdrive.com I would bookmark this page so it is easily accessible.
You will need to download Adobe Digital Editions and create an Adobe ID if you don’t already have one. Here is a link to download the needed software (Software Downloads )
On the website above, use advanced search to find something to checkout right away. Click on “Advanced Search” (on top-right of every page) and then enter an author you like. Under format choose the “Adobe EPUB” format. Then at the bottom, right above search, click the small box next to “Only show titles with copies available”.
After you find an eBook you like click on "borrow"
Next go to "My Bookshelf" click on "Download"
You may get a window that asks if you want to save or open a file. Click on “Open” and it will open Adobe Digital Editions and the “Setup Assistant” will ask you to sign in with your Adobe ID. If you don’t have one, you can get one here:Get an Adobe ID
After you sign in, your eBook will start downloading automatically.
After it is done downloading, connect your Nook to your pc and click on "Library Mode", it's the icon that looks like three books in the top left corner of the program. Then click and drag the title to your Nook on the left side of Adobe Digital Editions. Your eBook will then be on your Nook for you to enjoy.
If you have trouble, check out this great slide show on "How to Download an eBook": http://www.slideshare.net/WakeCountyPublicLibraries/how-to-download-an-ebook
If you would like additional assistance, we offer eReader one-on-one help sessions. Locations, dates & times are listed on our calendar at mysapl.org. Just click on "eReader Help".