The theory, from ERIC : You will find there a typology of sources and
pedagogical hints on how to use them
http://www.ericfacility.net/ericdigests/ed442739.html
Theory again, with how to use the different types of documents
http://memory.loc.gov/ammem/ndlpedu/lessons/primary.html
A lesson on primary source and how to use them
http://www.ohiohistory.org/resource/teachers/primary.html

The New Jersey Historical Society offers four sample lessons online that illustrate wise instructional use of primary source documents.
http://www.jerseyhistory.org/howtofind.html
The site suggests interesting questions, and gives hints for the answers.
Very interesting and complete way of analysing a photo :
see "dress making"
http://www.jerseyhistory.org/activity_photo.html
How to read a map and use it for historic information
http://www.jerseyhistory.org/activity_map.html
How to read and use a historic ad for historic clues (interesting!)
http://www.jerseyhistory.org/activity_recipe.html
how to work with an authentic text (a colonial recipe) (much more difficult)
http://www.jerseyhistory.org/activity_recipe.html