Primary document sites:
http://www.vlib.us/amdocs/
http://www.fordham.edu/Halsall/index.asp
http://avalon.law.yale.edu/
http://www.johndclare.net/
Have fun looking these up and hopefully you can get an idea of what is
actually out there regarding primary sources.
This page shows the sections and descriptions
http://www.montgomeryschoolsmd.org/schools/rmhs/departments/socialstudies/ibhistoryia/sections.htm
This page shows the rubric for scoring the IA - VERY important
http://www.montgomeryschoolsmd.org/schools/rmhs/departments/socialstudies/ibhistoryia/rubric.htm
A new search engine that might help you out too:
http://www.sweetsearch.com/socialstudies
And another one:
http://www.findingdulcinea.com/news/education/2010/march/101-Great-Sites-for-Social-Studies.html