Okay, these are in Spanish, but visually, they are a perfect introduction to triangle, or triloom, weaving:

• Part One
• Part Two

I know how to do a plain weave triangle, having woven several on the first loom I ever bought, a 24" triloom, but I'm now waiting for my 7 foot modular triloom to arrive, although I still haven't figured out where in the world it's going to go. 7 foot!