I was speaking with someone today with a MA in History, who was interested in getting involved with the digital humanities. She's keen to learn, but didn't know where to start.
My suggestion: take the best essay you think you've ever written and turn it into a webpage.
This will ground you in principles that will be forever useful as you progress to bigger and more complex projects, and it will give you a tangible 'deliverable' that you can be proud of. It is also something that you can teach yourself to do, with little instruction and a lot of experimentation.
Creating a simple website has many advantages. A lot of the advanced work you will do as a digital humanist will require you to work with webpages. This may involve dissecting pages from their source code, to extract content. You'd expect your surgeon to know what was connected to your knee bone; and I'd expect my digital humanist to know what was in my <:head> tag.
To get started, see my previous post "Putting a History Essay Online".
What about the other digital humanists out there? What's the best first step for an aspiring student?