Backstrap weaving is a period method of creating fabric. A ground loom is very similar and was used a lot by nomadic tribes such as the mongols as it was easy to set up and take down. In fact, they are similar enough that the same equipment can be used for both and swapping between the two is a simple matter of changing the way that the loom is anchored and tensioned.
https://web.archive.org/web/20150811224553/http://weavezine.com/content/backstrap-basics
This is a great tutorial that sets out using a continuous string heddle on a backstrap loom (the same heddle is used on a ground loom as well) and getting started weaving.
http://backstrapweaving.wordpress.com/
This is the blog of the author of the tutorial posted above. While it is written in reference to modern weaving in South America, the method of weaving on a backstrap loom hasn’t changed, and her clear and concise instructions make figuring it all out easy.
