Do you want to provide certification prep classes for your staff but can’t afford it. Well here’s an idea. There is a ton of free, open source material out there that you can use. You just have to put it together. Set up a document on your intranet, you can use a word document, a PDF or a web page, doesn’t matter, just use what you have available and are comfortable with.
Download the test blueprint from the certifying agency.
Past the URL of the YouTube video, the web page the wiki article etc, so interested people can access the content. Once people start using it, you can hold some informal on demand discussion on the subject.
The motivation for your staff is up to you.