I speak French better than Kreyol. Do you know any website -- or even book -- that provides the etymology of Kreyol words? Or that compares French and Kreyol vocabulary? Thanks!

Yes, you will find a lot of these kinds of resources, PDF files which you can download, and some google books, if you search the following names:

Michel Degraff
Morphology in Creole Genesis
"On certain differences between Haitian and French predicative constructions"

Comment écrire Le Creole d'Haiti by Yves Dejean

Quelques considerations sur les rapports de domination français-créole by Midy Franklin

La Fause Querelle du Créole et du Français by Dorin B.

Creole Genesis and the acquisition of Grammar by Claire Lefebvre

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words