Good reading is about asking questions of your sources. Even if you can't answer the questions, reading primary sources requires you to use your 'historical imagination'.
To help you analyze primary sources you can use the helpful acronym PAPER.
Use the list of questions below as a checklist to help you evaluate your primary sources. You can download a pdf version of the Primary Source Checklist.
Purpose
Who is the author? What is their place in society?
Why did they prepare this document? What's at stake for the author?
Do they have a thesis? What is it?
Argument
What is the text trying to do? How does it try to achieve this?
Who is the intended audience? How might this impact the author's strategy?
Is the author credible and reliable?
Presuppositions and values
How do the ideas and values in the source differ from the values of our age?
What preconceptions do we as readers bring to the text?
How might the differences in values impact the way we understand the text?
Evaluating Truth Content
How might this text support arguments you've read in other secondary sources?
What unintended information does the text reveal?
Which parts of the text are the author's interpretations? Which are historical 'facts'?
Relate
Compared to other sources, what ideas are repeated through them?
What are the major differences?
Which is more reliable and credible?
(adapted from Patrick Rael Reading, Writing, and Researching for History: A Guide for College Students.)