The first step program has many good ideas on how to write text forms.  You can find it online here.

http://det.wa.edu.au/stepsresources/detcms/education/stepsresources/first-steps-literacy/writing-resource-book.en?oid=com.arsdigita.cms.contenttypes.FileStorageItem-id-13760408

Teachers can develop their own examples for the students.  There is also a set of books that give samples of many text forms:

Comment écrire des histoires:

http://www.renaud-bray.com/Livres_Produit.aspx?id=1030479&def=Comment+%c3%a9crire+des+histoires%2cWARREN%2c+CELIA%2c9782923708102

Lettres et courriels:

http://www.renaud-bray.com/Livres_Produit.aspx?id=1030482&def=Comment+%c3%a9crire+des+lettres+%2fcourriels%2cWARREN%2c+CELIA%2c9782923708089

http://www.renaud-bray.com/Livres_Produit.aspx?id=1038964&def=Comment+%c3%a9crire+des+reportages%2cFAUNDEZ%2c+ANNE%2c9782923708096

Chenelière also provides books that help writing text forms like stories and opinions:

http://www.cheneliere.ca/resultats-de-recherche.html

The following site from Allo Prof provides also several examples of text forms and how to write them,

http://bv.alloprof.qc.ca/francais/la-grammaire-du-texte/les-types-de-textes-et-leur-structure.aspx