New 2021:
Nice illustrations for your lessons: free licenses
http://arbreaimages.wordpress.com/
http://www.iconfinder.com/
http://www.photo-libre.fr/
http://flickrhivemind.net/flickr_hvmnd.cgi?search_type=Tags&textinput=infrared
http://pdphoto.org/index.php
http://dryicons.com/free-icons/
http://www.iconarchive.com/
http://openclipart.org/
http://all-free-download.com/free-vector/
http://www.dragonartz.net/category/clipart/
http://www.cndp.fr/crdp-dijon/spip.php?page=clic_images&id_mot=33&men=t
http://www.clker.com/search/free/1
http://www.clipartpal.com/searchresults_pd.html
http://search.creativecommons.org/
My favourite site:
http://vectorgraphicsblog.com/
Simple pictograms
http://www.arasaac.org/ficha.php?id=6971&id_palabra=12619
http://www.sclera.be/index.php?taal=ENG
http://www.setbc.org/pictureset/SubCategory.aspx?id=58
http://catedu.es/arasaac/pictogramas_color.php
http://www.pictofrance.fr/Picto.aspx/catalogue
https://www.mindmeister.com/fr/416214333/trouver-des-pictogrammes-de-qualit?fullscreen=1
https://digital.library.pitt.edu/collection/visuals-foreign-language-instruction
https://thenounproject.com/about/
Coloring pages
http://www.edupics.com/coloring-pages-holidays-c88.html
Génial et simple d'utilisation:
http://blachan.com/shahi/
LIBRES DE DROIT
http://www.freefoto.com/index.jsp