When working with an ‘Edit Poly' modifier or ‘Editable Poly’ object you can quickly select an edge ‘loop’ or ‘ring’ with the below workflow.
1. With the chosen object, select an edge (using sub-object selection).
2. Now press and Hold ‘SHIFT’ when picking an adjacent edge. This will perform an automatic ‘walk’ around the edges in the direction that you chose. Below we can see the result of choosing the edge directly above the previous one. Note the flow direction.
This is a hugely time-saving shortcut when working with poly’s in 3ds Max.