Very briefly:
Before line-up, switch it on (provided no buildings / A/C are in front of you.
Line up on the runway and once lined up, tilt it up to max (15°), then slowly scan down till you have ground returns. Then tilt back to 5° up for departure. You typically achieve this kind of climb angle (depending on your A/C's performance)
As you get higher, you'll start scanning in such a manner to have ground returns on the edge of the screen.
Typically you'll have a setting of -1.25° (down) at cruise level (FL370). This also depends on range of your ND. Some people use 0° tilt in cruise.
Keep the GAIN in AUTO (general rule).
When descending, you'll slowly start tilting to the up position and during approach you will be back to your 5° up as you want to scan the missed approach path. Typically one chap will have the EGPWS on the other ND.
Use it as much as possible to get practice.
If VMC and avoiding CB's, you'll get an idea of what you'll be avoiding when avoiding embedded TS's.
As sed, very briefly.