Looking at the healing forum's stickies is good, mk?
Here's a direct link to the stickied guide to grid: Grid tutorial
I just downloaded grid, and it seemed to have plenty of indicators and things, but the question I have is if I could have a preview of the entire set of frames so I could tweak size and the setup of the columns and rows because I'd like to accomodate my party/raid frames at the bottom of my interface under my action bars and all since I have clique and it would help me on my healer.
I just was overwhelmed by all the fancy options and couldn't find exactly where I could do this.
Speak out! Ask for Stargate Atlantis to be brought back!
The tutorial doesn't really answer his question though. Your best bet might be going to Grid>Layout and Selecting "By Group 25" (or whatever frame size your trying to accommodate) as your solo layout. You won't get a populated Grid but it may at least show the overall size.
There is a section on modifying the size of the frames. It would also give good background on how to make changes in a more general sense, especially since he's also talking about using it for healing on one of his toons.