There are jobs around, but the pay and the conditions are not good at the moment, and Prague is nowhere near as cheap to live in as it was when I arrived thirteen years ago. You will be able to earn enough to survive, but you may be travelling all over town to get from class to class, withh a fair few early morning starts and late finishes.
The compensations are that Prague is a beautiful place to live in, and is centrally situated for travel. I have always found Czechs very pleasant people to teach.
If you have specific questions, PM/email me, and I may be able to give more useful information.