On e-teach, Michèle Carrougeau recommends this page of lesson plans and flash cards around the book : "the very hungry caterpillar"
http://curry.edschool.virginia.edu/go/wil/Caterpillar_Lesson.pdf

As a complement, I found the book online at
http://web.tiscali.it/scuoleinrete29to/cater/The%20%20very%20hungr[...]

and activities and resources around this theme on these pages

http://lilteacher.com/bugs.html
http://www.thevirtualvine.com/theveryhungrycaterpillar.html
http://hop.dartmouth.edu/assets/pdf/caterpillarstudyguide.pdf

( See p9 and 10, with diagrams of the metamorphosis)
http://www.teachers.ash.org.au/jmresources/kidpix/cater.html

(what the caterpillar ate)
http://www.tangischools.org/schools/phs/techno/slu/EDUC676/weque[...]

(a webquest)