You can get started right now teaching Spanish to your students even if you don't know Spanish yourself. Get started by watching "Mi Vida Loca." Your student will be able to complete a course of beginning Spanish in 12 weeks and will be able to watch 22 episodes of mystery adventure to Madrid and beyond. Each episode is 10 minutes long covering basic learning points of Spanish for absolute beginners. A learning section complements each episode. Go through the vocabulary and grammar in more detail and at your own pace, then complete activities for practice. I would say that the minimum age to start this series would be about 8 although you can give it a try for younger students and see what you think. Here is a short summary of the first episode: "The start of your journey to Spain doesn't go as planned. You'll have to fend for yourself in Madrid - and in Spanish."
What to do:
1) Watch the first episode You will be prompted to enter whether you are a male or female friend of Teresa's. If you have more than one student you may have to make a compromise or watch it twice.
2) Check out the syllabus for Mi Vida Loca to become familiar with the course.
3) Print vocabulary lists from here for the first episode and subsequent episodes.
4) Have your student rewrite the vocabulary from each episode as you go along. Then drill your student on the words.
5) Do the same thing for the grammar found in the same place as the vocabulary.
6) Assess your students using various techniques including speaking, reading and writing.
There's more! Go here to find more activities for beginners and intermediate Spanish learners.