Canvas provides a library of guides and instructions and you can find all the guides here http://guides.instructure.com/m/4212

Below are some to get you started! 

Help With Assignments:  

How do I view assignments? Guide  

How to submit an online assignment? Guide

How do I submit a text entry assignment? Guide

How do I submit a media file as an assignment? Guide 

How do I submit a peer review to an assignment? Guide

Files and accessing files 

How do I view files? Guide

How do I view my Google Drive? Guide

Canvas Features 

How do I use the calendar? Guide

How do I use the course home page? Guide

How do I view discussions? Guide

How do I view my grade? Guide 

How do I view a module? Guide 

How do I use the to-do list in the Dashboard? Guide