To help increase your site's SEO rankings, add metatags to your pictures.
Directions:
After inserting your picture, click on the picture. You'll see a little icon on the upper left of the image and popup text saying "Edit Image". You'll have a nice, full pallet to edit and add information to your image. Add the keyword phrase to the field saying "Alternate Text" on the first tab and "Title"on the second tab. Note that you can also link the picture to a certain, specific URL and then also set that link to open in a new window/tab.