You can access PubMed here:
Here are some tutorials created by PubMed to help users search successfully:
Web of Science is a good database to use, not only for finding scholarly research articles, but for looking at how they relate, respond, and inform other research articles on the same or similar topics. When you look at the record for an article in Web of Science, you can see what research the authors of that article cited. You can also see where the article you are looking at has been cited in others' research.
Web of Science has created several video tutorials to help use the database. Here are few that might be useful: