The Creative Commons has created a portal through which you can explore and find images that you can reuse. You can find it here:
Wikimedia Commons
Copyright can be very confusing. When a person creates a creative work, Canadian Law grants them copyright automatically. You cannot copy or make changes to a work without the permission of the author/creator, or unless you are in accordance with rights that are granted under the Copyright Act, including fair dealing. The University of British Columbia has created a handy guide to explain Fair Dealing, which you can explore further. Seeking out licensing (or getting permission from the creator) can be very time consuming.
Creative Commons is a nonprofit organization that helps overcome these legal obstacles. In order to do this, Creative Commons provide Creative Commons licenses and public domain tools that provide a standardized way to grant copyright permissions for creative and academic works, help to ensure proper attribution; and allow others to copy, distribute, and make use of those works. They also work closely with major institutions and governments to create, adopt and implement open licensing and ensure the correct use of CC licenses and CC-licensed content. Creative Commons licensing is an example of proactive licensing.
There are a variety of Creative Commons licenses. These include the following:
1. Attribution CC BY - This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.CC BY includes the following elements:
BY 
– Credit must be given to the creator.2. Attribution-NoDerivs - CC BY-ND -
2. Attribution-NoDerivs - CC BY-ND - This license allows reusers to copy and distribute the material in any medium or format in unadapted form only, and only so long as attribution is given to the creator. The license allows for commercial use.
CC BY-ND includes the following elements:
BY – Credit must be given to the creator
ND 
– No derivatives or adaptations of the work are permitted
3. Attribution-NonCommercial - CC BY-NC: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator.
It includes the following elements:
BY – Credit must be given to the creator
NC 
– Only noncommercial uses of the work are permitted
4. Attribution-ShareAlike - CC BY-SA -
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.
CC BY-SA includes the following elements:
BY – Credit must be given to the creator
SA 
– Adaptations must be shared under the same terms
5. Attribution-NonCommercial-ShareAlike - CC BY-NC-SA: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.
CC BY-NC-SA includes the following elements:
BY – Credit must be given to the creator
NC – Only noncommercial uses of the work are permitted
SA – Adaptations must be shared under the same terms
6. Attribution-NonCommercial-NoDerivs - CC BY-NC-ND: This license allows reusers to copy and distribute the material in any medium or format in unadapted form only, for noncommercial purposes only, and only so long as attribution is given to the creator.
CC BY-NC-ND includes the following elements:
BY – Credit must be given to the creator
NC – Only noncommercial uses of the work are permitted
ND – No derivatives or adaptations of the work are permitted
Please note that all above information comes from the Creative Commons website "About CC Licenses"
Here is a great infographic created by Foter that will help you understand the various licenses:
CC License Requirements - Foter - CC by-sa 2.5-ca
Please note that this guide has heavily borrowed from the wonderful work done by the University of British Columbia and their Copyright at UBC site, and more specifically the Creative Commons Guide.
