M mode on G6

How do you really use the manual mode on the G6? I never actually understood how to use it to its potential. I have tried it, but I can't get the thing to change to the aperture value for me to change it. It always starts at the shutter speed, but i can't seem to change it to the aperture value. How can I fo this?

Try this...
You know the wheel that you are moving to change the shutter speed ... it's clickable! The black one located at the top of the camera behind the zoom button You can actually depress it a bit to toggle between the two settings. I actually figured it out before I noticed it in the manual when I was goofing around with the camera. It was a nice a-ha! moment

Also, when you half-press the shutter, the exposure will be shown in the upper left of the LCD. Just raise or lower the shutter or aperture until you have the exposure you want. Usually you will have either a shutter speed or an aperture value you are interested in. Set that one first, then adjust the other to get the proper exposure. If you can't get the desired exposure, sometimes you can change the ISO, which moves the range of settings.