I have not seen inside Top Notch books, but it is suppose to be based on real life language. The books are from authors who have been teaching in the US/Chile/China. Although teaching is pretty much the same around the world, you may benefit from relating it your students specifically. For example, when in China my book (not Top Notch) did not relate well to my students – it would ask questions about who washes the car (they had no cars) or about films that many of my students never even heard of because of restrictions in China. However, I was lucky in that I could diverge quite a lot from the book and use my own ideas based on what the students liked. So I tried to mix the book with my ideas. I am not sure if you can do this in Iran and if your principal would allow it or not. Can you use your own style or will they expect you to conform to their methods? Also are you teaching mainly spoken ? Are your students in Iran better at reading and writing than speaking and listening ?
I am sorry if I tell you anything you already anyway I normally try to follow the Engage-Study-activate stages of lesson planning. 1) So in engage I need to get students interested in the lesson e.g. show pictures of new vocabulary to learn. 2) Study – for example pronunciation and meaning of vocabulary 3) Allow students free time to practice - perhaps put them in pairs and get them to practice whilst you walk around the room and observe. You should also have very clear aims about what you want to teach at lesson start: ie not just to learn ten words, but to learn 10 words in spoken form, using pictures etc. You should also read up about the multiple intelligence theory.
Get as much information about the students before you teach them. Email other teachers.