In October, I took a teaching job after leaving a school I had been at for 4 years. I left that job because I was frustrated due to a lack of behavioral support for the students. My new job is NOT the place for me, due to the ineptitude of support staff and lack of resources. I am now looking again for a new teaching job. Should I include this 4 month position on the resume, and if so, what reason should I give to the interviewer for leaving the position?
Unless you have learned something so valuable in those four months that it will help you in getting the next job, it is better to just leave it off.
However, if you're currently still employed and looking, you should be honest and clear things up if they think you're still working at the older job. You can let them know that you were not a good fit for this current job and so you're looking for a job where you will thrive. So, you're making sure that they are a place you want to work, as well as them making sure you are what they want. You don't want another short stint for a while.
If you've already quit, then it will look like you've been unemployed for at least a short while. Hopefully, you haven't already quit, because it's harder to get a job when you're currently unemployed.
There are a lot of related questions and a lot of good advice on this site already, such as Is it OK to leave very short-term employment off my resume? and When should I tell an interviewer I left my old job?
Simply state that you feel the position is not working out, that you expected a certain level of support from your superiors to achieve your work goals that is ultimately lacking and that you find yourself looking for an environment where you can truly succeed. There's no need to get into details, in fact it may reflect poorly on you in an interview if you are badmouthing a former/current employer as the interviewer may infer that you would do the same to their company.
I once had an interview where I had to explain why in 9 months I had moved between 3 different jobs, staying at each roughly 3 months at a time. I was frank and honest and said that working conditions and the hours and pay I was promised when I was hired at all 3 jobs did not appear in reality. I went on to be offered that job and worked there as a solid employee for fair length of time.