How to attach an image to Gmail
Screencast Here

From your Gmail account, click 'Compose Mail'.
Click 'Attach a file'
An additional  will appear. Click 'Browse'.
A File Upload winidow will appear.  Pull down the 'Look in' menu an find the folder that contains the file you'd like to attach.
Click the file and then click Open.
It might take a while for the image to attach. Wait until you see a line with a paperclip, checkbox, filename, and filesize.  When you see that, it means the file is attached.