A lot of researches have been done over years on the importance of using visuals in the ESL/EFL classroom for our students' learning process since images allow them to infer, deduce and provide the context to clarify the meaning of written texts.
A great resource for teachers that I discovered three days ago is My English Images, a website created by F. Michael Kloran, an English teacher and illustrator living in Japan with a very personal style who has decided to create this site to make other teachers' life easier.
In this site you will find a collection of ESL resources, mainly pictures and worksheets to spice up your classes, which have been grouped into different categories:
All the worksheets include and introduction and clear explanations about how to use them in the classroom. These materials are copyrighted but you can download them for free in PDF version. Beside, if there is something you cannot find here or you would like to make the author some suggestions, you can contact him in the e-mail address provided in the site.