How can I snap edges to grid lines? I am very new to Blender and I'm having some trouble with grid snapping. 
I have absolute grid snapping enabled. If I select an edge or edge loop and attempt to snap to grid, it snaps in the correct increments, but not exactly to the grid lines. However if I select a singe vertex it snaps to the grid lines perfectly. What am I missing? 

Any help is greatly appreciated, thanks! 

Scott.
Snap &gt; Increment with ✓ Absolute Grid Snap seems to work fine.
To have more precision

switch to Ortho view (View &gt; Perspective/Orthographic, Numpad 5)
use a top/side/view (View &gt; Viewpoint &gt; Top,  ~ )