Ubuntu (Linux) vs Windows device plug and play compatibility
Solution 1:
Shortest answer: Yes.
Longer answer: Unless the device is brand new, strange, or just something that fell through the gap, anything plug and play on Windows will likely be plug and play on Ubuntu. Don't assume, though!
Plug-n-Play is an interesting term. There are multiple kinds, each doing different things - for example, a device like a keyboard that needs no special driver at all is plug-and-play, but technically so is the device that downloads its drivers through Windows Update.
Anything in the "generic" category will almost always work on Linux straight away. You should be able to plug in almost any keyboard, mouse, flash drive, etc. without any issue. You may get the rare device that doesn't want to work due to some quirk, but these are few and far between.
Things that download drivers in the background (quite a few webcams, printers, etc.) are more of a mixed bag. In my personal experience, these have almost always worked fine on Linux, but this is not always the case. You may need to install printer drivers or other things manually if the Linux kernel doesnt come with a working generic.
In your case specifically, I would hazard a guess that your barcode scanner will work just fine under Linux without anything fancy. Unless you got a very high-end (or very weird) barcode scanner, it will just expose itself to your computer as a keyboard. Keyboards don't need anything special, so it should Just Work™.