Music Theory Software

[shingo]

Hey,
I am looking to improve my theory and although I go through it with my tutor, I wish to be able to practice it and keep on top of it at home and in my own time. First of all is there any decent software avalible  for this as I find it much easier to learn theory with visual aids i.e more so than a book. I have looked around amazon but to be honest nothing stands out as being amazing, so I wondered if anyone here had some experience with some and could recommend any. I need it to cover up to and above grade 5+ if possible. However if none of this software is particularly helpful (which I wouldn't be surprised if it wasn't) could anyone recommend any useful books again covering up to and beyond grade 5 level.
Thanks.

[sarask_76]

I am using Yamaha Digital Music Notebook. It is free to download and I used their lessons before I take lessons from my piano teacher. It is free to download and use it. They have free lessons and I paid for some lessons. They cost somewhere around $25. It helped a lot. I am still looking for recommendation for better software.