Arduino controled HIFI Preamp

Hello everyone

I am new to the world of microcontrolers. I am working on a HIFI Pre AMP to run a power Amp I built few years ago. I got an Arduino Mega off ebay that came with a ks0108 128*64 GLCD screen. I want to create a menu to select different sources (CD DVD Radio etc) and use a rotary encoder to select items from the menu. I have found lots of sample code for doing this with a standard 20x2 LCD, but nothing for using my big GLCD. Can someone please point me in the right direction. Also I would like to create a volume level display and remote control. This is a sample of what I would like to do, only on bigger screen.

I have been thinking it would also be fun to create a spectrum analyzer on this display.

Thanks in advance for all your help

Sorry don't like bumping post's, but could really use some help