Primary sources are the raw materials of all good historical research.  Original documents and artifacts produced during the period you are investigating or at a later date but from personal memories of participants or observers of historical events, as well as any quantitative data drawn from those documents or artifacts.  

Items such as:

• letters, diaries, journals
• Manuscripts, speeches, interviews
• paintings, drawings, sculptures
• photographic images, audio recordings, film or video
• government documents, court cases, census data, economic statistics
• pamphlets, factual newspaper articles
• materials unearthed at archeological sites, coins, medals
• clothing, tools, flags, weapons
• songs, stories, novels, plays
• marriage license, deeds, certificates

Start with a list of questions about:

• author
• context - who is talking to whom
• time period

Strategies

• sourcing- think about the documents author and its creation
  • who created it
  • when
  • for what purpose
  • how trustworthy is it
  • why
• contextualizing-situate the document and its events in time and place
  • what are the major events of the era
  • themes
  • who is the audience of this piece
  • see it through their eyes and world not ours
• close reading-what the document says and the language it uses
  • I've never heard that expression before
  • that may be a reference too...
  • I wonder if that's what really happened
  • read the silences- what is not be mentioned, whose voice is not being heard
• corroborate
  • check multiple sources for details that agree or disagree