There are two ways you can search the Medline database. See your options below:
Use the Advanced Search and History in PubMed to give you more search options
Use Medical Subject Headings (or MeSH) tell you what each article is about (think hashtags!) Use the MeSH Database to search PubMed in a very targeted way.
The MeSH Database can help you search PubMed to find
Find definitions of the article types (a.k.a. "publication types") used in PubMed. Click on "Additional Filters" in the PubMed filters to see all the article types. This can help you find the best evidence available for your topic or filter out sources that might be unhelpful (books or preprints, for example).
You can get references into a reference manager in two different ways:
Ulrich's International Periodicals Directory can help you answer these questions. Simply search the journal title to determine if it is peer reviewed/refereed (look for the tiny referee shirt). Ulrich's will also tell you if the title is a trade magazine or journal.