The OpenTechSchool is an OpenSource Community. We do publish all our materials under Creative Commons and want others to build upon them. But that also means all our source material needs to be under an appropriate licence. And that can be quite hard, especially if you are trying to create a visually appealing presentation (like this hackership one) or just look for a really nice picture for the blog post.
This is a short overview of tips and tricks to make your life easier finding those.
Think of good representations for what you want to visualise. Unfortunately verbs and too specific wording is nothing you'll find good pictures for. Thinks of associations and relative things that people do take pictures of. Example: instead of schedule think of how to represent time; instead of courses or learning material think of an amazing looking blackboard in a university.
Also, no matter the licence, make sure to refer back and give credit for the work.
Lastly, publishing a picture (on a blog or presentation or website) is understood as "journalistic work". That means, if a clearly identifiable person is the main attraction of the picture, you also need to make sure they are okay with a picture of them used in this context. This does not apply if they are just part of a bigger composition or not clearly to identify. Generally keep your hands off celebrities, who didn't release the pictures themselves for that use.
The number one source for amazing images in high quality is still flickr. In their new redesign they now have a handy way to select only creative common results when searching. On the result screen just take a look right above the first row of pictures and you'll find these great filters:
Just select "Commercial use allowed" and off you go. And also switch "relevant" to "interesting" to have them sorted in a better way.
There you go.
Wikipedia has one of the largest collections of free-licence pictures, to be found on Wikicommons. Navigating through it might not be super easy with all the categories and stuff, but you get there eventually.
Once you found a picture, you still need to make sure they are under an appropriated licence by scrolling down on the image page to the Licence section:
If it says free to share and remix, attribution and share alike, you are fine. Again, attention, when it excludes commercial usage as – legally – what we do is commercial.
One of the best resources for finding images is the google image search. And same as flickr, they do have an option to only show those images which are clearly marked as having a free licence. Unfortunately that is even more hidden than in flickr. After you searched in google images, click on the cog-icon on the top right and in the menu select "Advanced search".
Again at the bottom of the options you'll find the drop down for "usage rights". Switch it to free to use, share or modify, even commercially (the last option in the list):
Click "Advanced Search" and enjoy your results.