for the jalapenos, look for the ugly wrinkled ones, the more wrinkled, the more they will burn you, and the less english the seller speaks, the more potent the hate of the pepper will be.
Boil tomatos first until soft, then throw into a blender, then get a gas mask unless you can take the pain. Boil the jalapenos until they are also soft (seeds in or seeds out is up to you, but keep them in for more pain), and boil until your lungs cannot take it, or the jalapenos are soft.
Then shrimply blend both in your blender until its at a consistency you like.
The salt is to lessen the pain of the peppers, add liberally until its at a heat you enjoy. Once it finished, take it to your work, watch as some of your co-workers either embrace the pain, or start crying.
Enjoy!