You're best bet is to apply directly to the universities. I'm not so sure about the use for legal English. There are loads of ESOL positions, though. They require a MA TESOL, a few years experience (preferably post-secondary), and the pay is anywhere from 10,000-18,000 dirhams/month plus accommodation, airfare, education for kids, plane tickets, etc. Instructors who teach content tend to earn a bit more than the esol teachers. I don't know that there's a great demand for sociology instructors, though. IT, Business, vocational subjects-these are more common.

Start w/ Zayed University, UAEU, Higher Colleges of Technology, and American U of Sharjah. There are also other institutions which have opened up in Education City. Recruiters in this field are a no-no. Go straight to the uni, do the online application (if they have one), and then see how it goes. Most institutions, however, have already recruited for the upcoming academic year. It doesn't mean you don't have a chance for an August/September hire. It's also possible to find work mid-year, though less likely.

I should warn you that many of these online apps are REALLY time consuming. Best to line up all your details (referees, jobs, dates of employment, philosophy of education, etc.) before sitting down to crank out the apps. I hope that info was helpful!