Changing Chart Size
Once you have your chart started you might decide it's the wrong size. Maybe you get halfway through drawing it and realize it's one row too small, or you want to take out a column in the middle. No problem.
Around the edges of the chart you will see plus and minus symbols. Click a plus from across the top and a new column will be inserted to the right of the plus symbol.
Click a plus from across the left side and a new row will be inserted below the plus symbol. The new rows and columns that get inserted are in the color you've selected, but they're easy to recolor if you forget.
Click a minus and the row or column it's on will be removed (you will get a popup window asking you to confirm the deletion, just to be safe). Notice that a yellow border appears around the cells that will be deleted. Fancy, huh?
You can add and remove rows and columns anywhere in the chart. Since rows and columns are always added after the row you click on, the very topmost plus sign on the left adds a row before the first row. Likewise, the leftmost plus sign at the top adds a column before the first column.