I am doing a grade 9 debate and was just wondering if you could help.

Read all sorts of very recent pros and cons by googling 'Wisconsin teachers strike.'
The right for teachers to strike goes by state, and many are having problems as budget cutbacks increase.
The feds have moved in at times (Reagan decided he had the right to keep air traffic controllers from striking).
It's a never ending battle with many types of taxpayer funded employees who people consider vital.
What is your opinion?

Not sure which side of the debate your on. But here is a problem you face when teachers or public employees go on strike. Money is already allocated in the form of a budget. Any new monies have to come from the public in the form of taxes. In the private sector there are budgets also but money to pay for raises can come from profits or from raising prices. Both are indirect sources. So you can see the tug of war when negotiating wages

As a debater were you assigned a side, pro or con?
As with many political processes, the right to strike has a short view and a long one. Children go untaught while teachers either picket, stay home, or bargain, instead of working out contracts outside of a strike. On the other hand teachers still are suffering from an old 'school marm' tradition of being the bottom of the pay scale when they should be the top. There are toll booth collectors who make more than many teachers, with no skill or education past high school.
So again, what do you think?

Can you back up the claim that teachers are at the bottom of the pay scale? Not anywhere that I have heard of lately with exception to private schools.

True, not lately.
Teacherportal.com has salaries for all 50 states. About 17 states have starting salaries under 30K.
It has always been a sour joke in MA where I lived for a long time that toll booth collectors made a lot. One quote I found from 2008: "NBC News Boston reported this morning 9/18/2008 that the average salary of a toll booth collector in Massachusetts is $70,000." (Don't try to get a job there - all nepotism.)
The salary range for a MA teacher is about 35 starting and 56 average.