A useful information source is the website of the Industry, Commerce and Labour Authority of Dubai, as this is the government body responsible for hiring foreign professionals.
Yes, a work permit and visa is required. The procedure for obtaining the permit and visa can differ from country to country, and must be carried out prior to starting work in Jabal-Ali.
You will need a recognized teaching qualification at post-secondary level, together with relevant classroom experience.
Salary levels for teachers can depend on your qualifications, experience and language capabilities. Generally speaking, salaries are competitive with those available elsewhere in the region.
No, it is not essential to speak Arabic to teach in Jabal-Ali, although it can be useful if you want to interact beyond the classroom. English is widely used as the language of instruction for foreign students.