Sorry: I think you'll need to upgrade to CVI 7.0 for that. Then you can control the grid by opening a UIR file and going to Options >> Preferences. You can select whether you want to show the grid, the type of grid (dots, lines, etc.), the grid spacing, and whether or not you want to snap to grid.
In CVI 6.0, your layout help is limited to the Arrange menu in the UI editor. You can choose the allignment and distribution, and, under Arrange >> Control Coordinates, you can specify a group of selected control to have the same size.
You can download a trial version of CVI 7.0 (356 Meg!) from http://ni.com/lwcvi/launch.htm
