Help needed with OverDrive Media Console app
My understanding is that the only way you can transfer WMA files of audiobooks borrowed from your library to your iPhone, iPod, or iPad, is to use the desktop version of OverDrive Media Console on your PC. This has a transfer option in the software that allows you to move files downloaded onto your computer to the attached device using that program rather than iTunes synching. You can't move them to iTunes because the Windows Media DRM protection prohibits this. If you had borrowed MP3 files, you would be able to copy these or add them to your iTunes library, and you would be able to sync them over just as with your music files. In fact, MP3 files of audiobooks that you borrow through the OverDrive Media Console app can be downloaded directly to your iOS device through the app, with no need to connect to a computer at all.
I don't use a PC, but I have used OverDrive Media Console on the Mac, when it was released in an accessible version several years ago. Sorry, but there is no way automatically transfer WMA files to your iOS device. I think you may be able to transfer files using the desktop version of OverDrive Media Console with your iOS device attached, though. Make sure that you have all the updates that are required for the WMA DRM certification. If you can play the WMA files in the Desktop version of OVerDrive Media Console on your PC, I beleive you should also be able to transfer them to your iOS device. I did use the Mac version of the desktop software to transfer MP3 files to my iPod nano, many years ago. Good luck.
OverDrive lets you add multiple library locations through the "Add a library" button, and each of these may use a different library card. While the usual library use model in the U.S.is that access to your local library is free, and you are issued a library card once you demonstrate proof of residency, like a recent utility bill with your name and address, that's not necessarily the model for other international locations served by OverDrive. Even in the U.S., there are instances where people might have access to more than one library or library card. For example, if you live in another location for part of the year, or if you take a summer job or do an internship somewhere, or go off to college, you may have more than one library location and library account number that you use with the app. For these reason, the OverDrive app doesn't permanently store a single account number. It's also typically interfacing a standard web page maintained by your public library through the app, which could be used from a public computer.
You could store your account number in the Notes app or other app, and then use the app switcher to copy the number, switch back to OverDrive, and paste it in.