Needless to say, learning Vocabulary is essential!!! and obviously, FLASHCARDS is one of the best tool to teach and learn new English words, especially for kids. So, let's see this fantastic web SUPER SIMPLE LEARNING, here you can download fantastic flashcards totally free! (Besides, you can find SONGS, FREE RESOURCES on this web, don't waste time and click).
If you work with children, you can teach new words thanks to these flashcards, you can make up a story with these new words, you can even bring or point out the real objects, etc. You'd better use your teaching skills to get your students involved. For example, if you want your students to learn some vocabulary related to fruit and vegetables, you can bring them some real fuit and vegetables, they'll touch them, they'll feel more motivated, ... This is always more interesting and encouraging for them.
Teaching and Learning is always FUN!!!