Do you mean just uploading images?
You must go to an online image hosting website.
I recommend getting an account on Photobucket.com. Getting an account is free and Photobucket works great.
Once you get and account. You will see a button that says "Browse."
A small window will pop up. Look for the folder that contains the image you're looking for and then click "Open" on the window. You will be back at Photobucket. Click the "Upload" button.