When most office workers get word they're going to start managing the books, the first thing they do is open Microsoft Excel. Which, of course, is the right thing to do. There's no better way to keep track of any kind of data, especially when the job requires you to do calculations on the fly.
Unfortunately, many of those same amateur accountants never really dive deep enough. They might use Excel for data entry and find it perfectly reliable, never realizing that this powerful software can not only make their work easier—it can actually handle some of the heavy lifting by itself.