You can always send someone detailed instructions on what you need, but often times it is easier with pictures. You can take screen captures on our computer screen, mark up what you want done and send the capture to your team member. Sources include :

SnagIt.com - Take a picture or make a video of anything on your computer screen.

Jing.com – Jing captures anything on you see on your computer screen, as an image or short video, and lets you share it instantly