I'm trying to teach all of my friends Esperanto but I'm not entirely sure where to start with the language

A handy booklet that gets you started is Poŝamiko. At least Esperanto-Asocio de Britio (EAB) sells it at their shop, but probably your local association sells it too. The booklet teaches everyday words like clothes, food, drinks, body parts and so on.

This site Lernu has a highly recommendable course La teorio Nakamura which begins with the basics and gradually progresses. Do not forget the grammar section.

There is also a site called UEA facila which contains easy texts.

I suggest you begin with an introduction to the basic grammar (word types, tenses) and pronunciation. Not very deeply, just so that you can begin to read simple texts and learn more by reading and understanding them. Or why not embark you all together to that Nakamura-course!

Dankon multe, Metsis ! This helps a lot :}}}}