Case
Trying to find a school

How early do we start looking for open teaching positions? how do we know what to bring and be prepared?

Solution #1
If you are in your internships you should be figuring out what district you want to work in and keep an eye out for openings. However, you won't be able to start until the next semester, or the next Fall school year. You don't want to apply too early. You never know - maybe the school that you're interning at might offer you a job!
Solution #2
I think during your last internship or semester of college before you graduate, you could start applying to schools that interest you. In your application you can explain that you are graduating soon and wanting to get a head start on figuring out your job/future. Some schools/principals might really respect it, and you may get hired before you graduate. I think you should dress professionally, bring your school grades, and any work that you have done as an intern that you are proud of.
Solution #3
Teaching postions are available on the school district website. Always bring resume, certificates, recongition awards, and anything else that is related to the career.