How do you produce original content if you're just copying?

Practice :P. You need to be able to draw before you draw and come up with new things at the same time. And generally people have a lot of references and such when they are coming up with new things.

Also, how do you possibly draw digitally without one of those fancy pad things?

Mouse? The latter images I drew on my 3DS. The former were done with a mouse. With no pad/stylus, you definitely have to go a bit slower. But there shouldn't really be a difference.

I'd definitely have to see what I wanted to draw, because I can't hold an image in my mind at all. If I concentrate, it just slips out of my "mind's eye" and everything is just blobs.

Yup. Draw what you see, get good at that. A lot of artists have done this. Once you start getting the hang of it, then draw new stuff (by drawing a bunch of various references in a particular way :P).

Even with something like Anime, they still use a ton of references. Backgrounds? They go around, take a picture, and draw that picture in 'anime' style, adding or removing things as desired.

Naturally imaginary/fake stuff is a bit trickier, since you don't have an existing reference. But say you want to draw a robot or alien or something. Find existing ones that are sort of similar to what you want to do. Take your time to get the various characteristics and such. And draw what you see, but put your own spin on it.

It's not going to ever be a 1-to-1 copy, and generally you can get a good idea of how to add variety once you get going. Again, liberal use of the eraser is key.

Thanks for the tips. I'll see what I can learn for free before actually throwing money at it. I really would be interested in figuring out how to draw half-decently!

Take a pad/pencil, and just pick some random object each day to draw to the best of your ability. Take your time and be sure to capture the shadows/shape/etc.

As I mentioned, I personally grabbed Art Academy for the 3DS, which worked wonders. I hear bob ross' videos are good for learning to paint.

Patience+Technique+Practice=Good art.