As far as Moodle is concerned, a link to a file in the course File area is just like a link to a web page. This might be a bit confusing at first. The best way to think of it is that you can link to a file or link to a web page. Either way, it's still a link. Return to your course front page and make sure that editing is turned on. If editing is turned on, then you will see the Add a resource… and Add an activity… drop-down menus at the bottom of each week/topic:
In the topic in which you want to include your link, click on Add a resource... and choose Link to a file or web site.
Give the new resource a name. It could be just the name of the website you are linking to. I'm going to call mine "Firing a bullet from a gun", because that's what the website I'm linking to is about.
Copy the address of the web page into the Location field. I'm going to cut and paste my website from the Word document that I have.
You can also find a website...