This guide is written for use with DOSBox 0.74, the latest version as of April 2014. Travellers from the future might run into inaccuracies. Sorry about that.
DOSBox is scary if you don’t know how it works. I’ve spoken to many a would-be DOS gamer, eager to explore the classics of the pre-Windows era, but are held back by the unforgiving text-based monstrosity that is DOS. While DOSBox may be an emulator, it’s a pretty faithful one, which requires at least a grounding in DOS to get the most from it.
And if you’re looking to get the most from it, I’d recommend checking out Abandonia’s excellent guide on using DOSBox, as well as browsing the official Wiki.
If, on the other hand, you’re just looking to get started in the emulator as fast as possible, I think I can help!