How long does it take to learn how to use MadCap Flare?

For the very basic features like moving around the interface, adding topics, and creating targets (i.e., output), you can be productive within a couple of days. However, if you want to truly leverage the power of single-sourcing and context-sensitivity, you're looking at a steeper learning curve of probably a month or so. That's about how long it's taken me to train the various writing teams I've had the pleasure of training. Of course, they were productive within a week. But, there's usually a good bit of hand-holding for about a month. Flare is an incredibly powerful and versatile tool. Honestly, I've been working with Flare since 2005 and I'm still discovering new and fun capabilities.