Note that newspaper articles can be used as primary or secondary sources, depending on context!
The History of Science, Technology and Medicine (HSTM) and IsisCB are two very important databases for STS! JSTOR is also very useful, especially when using the "advanced search" feature.
In secondary sources, authors analyze and interpret primary source materials.
Secondary sources can be scholarly or popular. Scholarly sources (sometimes called "academic" or "peer-reviewed" sources) are written by and for experts and typically include bibliographies and citations. Popular sources are written for a general, non-expert audience and can be authored by anyone.