I have been working on getting my Microsoft Word, PowerPoint, and Excel certifications whenever I have time. The word and power point are fairly easy. Excel is harder because you need to know math equations and how to set them up.
You can take many different practice tests and then take the the final test. You can do as many practice tests until you feel comfortable. There are usually only 5 or 7 questions per project and there are only 7 projects in a tests. Getting certified can help you find jobs and just help you in general if you have to use a certain program.