If you're finding this heavyweight robot simulation heavy going, give the following hints a try:
Disable overheating
If you're piloting a Mech that shuts down or explodes when performing an alpha strike, press the 'F' key as soon as you've performed the strike to stop your Mech shutting down.
Salvaging
Group a lot of medium pulse lasers together and concentrate your fire on one leg of an enemy Mech. This should immobilise the Mech and make it easily salvageable.
Watch a video
Watch any of the in-game videos by going into the Video folder on the Mechwarrior 3 CD.