There are a lot of things I love about digital painting, and I will defend it against anyone who suggests that it's "cheating" or "not real painting." However, if you are just starting to learn how to draw, I don't recommend starting with digital painting.
The only way to get better at drawing is to draw a lot. Artists like to say that everyone has to create 10,000 bad drawings before they can start creating good ones. While this is an oversimplification, it's also very helpful to keep in mind.
If you're just starting out, you'll probably make a lot of bad drawings and it will be frustrating, and you'll start looking for ways to avoid that frustration. This is natural, but it also leaves you vulnerable to the siren song of digital painting, which promises easy answers and quick fixes. Here's why I don't think you should leap into digital right away:
1. Learning the programs will distract you from drawing. Photoshop and Illustrator have a lot of little buttons to learn about, and keeping track of your layers and preserve transparency settings takes some getting used to. If you're also learning the basics of drawing, it can all be overwhelming - and possibly make your drawings worse.
2. Fancy brushes and textures can be a crutch. Many digital beginners place way, way too much emphasis on different kinds of brushes and textures. These texture brushes can come in handy, especially if you're a concept artist who needs to render things quickly. But they can't replace drawing skill, and it's easy to spot an artist who relies on them too heavily. (See Chris Oatley's post on "the Texture Monster.") Don't think that using a tree texture brush is the same as learning to draw trees.
3. You'll want to buy the most expensive equipment. Trust me, it's only a matter of time before you meet a Cintiq evangelist and start drooling over that $3,000 piece of equipment. You'll start to tell yourself that your drawings would be so much better if you had the really good stuff. Yes, it's important to have decent equipment, but don't think that fancier hardware will save you from having to get through those 10,000 bad drawings. As an analogy, think of a person who wants to lose weight and get in shape, but keeps fretting over having the perfect running shoes or the best treadmill.
If you're just beginning to learn to draw, keep it simple: get a pencil and some paper, and start drawing. If you can go to some life drawing classes, that's great, but don't fret too much over buying the right books or watching the right tutorials or buying the right Wacom tablet. Just draw.
All you need is to wrap your hand around a pencil and draw.
Note - if you are already doing digital and you enjoy it, don't stop. I would never tell someone to stop drawing in a way that they enjoy. But make sure that you're practicing traditionally too.