I teach kids of different ages, we don�t use a text book as I work in an Academy (we use written material such as readings and worksheets, we encourage the kids to speak in English as much as possible and use a lot of games and songs), my question is, do you know of any sites where I can get an idea of what children, depending on age and level, are supposed to learn, it would be great to know structures, verb tenses, vocabulary...etc, they are to know. Thanks in advance for your help.

You should look for you countries national curriculum  and then for the English syllabus. When I visit the site of the Portuguese Ministry of Education, there �s an option with the syllabus of all subjects in the Curriculum.