Below is a simple sample search in PubMed.

In the search box on PubMed's homepage, put some search terms to see what information there is on your topic.

Click on Search.

On the left hand side of the results page is a graph that shows the number of results per year.

You can slide the circles at the bottom of the graph to change the date range.  The search results will refresh to show results that match the new dates.

Also on the left hand side are options for Text Availability.  This is a bit misleading.  There is an option for Full Text and another option for Free Full Text. 

Free Full Text does mean that it is freely available and immediately accessible.

Full Text means that there is a link to the publishers' websites where you can purchase the full text.

Here is an example of how to locate the full text links, free or otherwise.

On the next screen, look over to the right hand side for Full Text Links.  There you will see the links to either access the article immediately or, as in this case, the link to the publisher's website where you can purchase it.

Please see the tab labeled Is an item available in the Purdue Global Library? to see if an item is available in the Purdue Global Library.

Here is what a Free full text article will look like in the results list.

Free PMC article indicates that it is freely available in the PubMed Central database.

Free article indicates that it is most likely an open access article.

One last item to note down the left hand side of the results page is Article Type.

Here you can select the type of article to show in the results.  This is helpful for nursing courses where you are asked to find a specific type of research article like a randomized controlled trial or a meta-analysis.