A statement of teaching philosophy is your opportunity to discuss your motivation and preparation for a teaching career. In your own career as a student, what kinds of teachers motivated you?
In your teaching experience, discuss the strategies you tried, which ones worked and which didn't. Mention the courses you are prepared to teach (again, teaching assignments will be part of the job negotiations) and what topics you are interested in teaching. Focus on courses across the curriculum, from undergraduate to graduate, keeping in mind both what is already in that institution's course catalog, and what new courses you might be uniquely qualified to teach.