Actually I'd agree with Graham. Music is the art of hearing, not viewing. Of course we read music sheet, but in no serious concert you'll see musicians reading it. After some practice, hearing takes over...
If you're not into classical music (which is the case since you are going for a keyboard and not for a piano), then try to use your ears as much as possible. Some people can't, but I think that most can do it. Try it. My choice would be a used keyboard until I realize what suits me...
Good luck with your learning, and remember that one way or another, you're entering a wonderful world! But I think you'll get the most of it by using your ears to hear, your fingers to play and your soul to feel...