Wikipedia:Image dos and don'ts

Images can make Wikipedia more informative, accessible, and professional.

Therefore, when you illustrate an article:

DO:
Be familiar with the image style guide and use policy.
Try to find at least one image to illustrate each article.
Check free image sources for suitable images.
Create and upload your own images.
Clean up images: crop, color-correct, etc.
Choose the best file format for each image.
Caption images helpfully, and provide alt text.

DON’T:
Don't upload images that lack a free license.
Don't add images that don't relate to the subject.
Don't overload articles with images.
Don't flip artwork, text, or faces.
Don't use an image if an editable table could be used instead.
Don't use a fixed image size larger than 220px.
Don't sandwich text between two images or boxes.

Also:

Do consider joining WikiProject Images and Media.

See also