Searching for and presenting images

You can add an image to your Moodle site via:

a label

a book

a summary

a file.

One each of these you'll see a WYSIWYG editor (what you see is what you get). 

There is information in the Setting up your course in Moodle module and the  For Staff section  

Add an image

For accessibility and usability issues it's a good idea to name the file.

Important note: do NOT resize the image in Moodle because the image will render differently in different browsers.