I don't have a Turbo, so I can't say for sure where the button would be, but on my app it's a paperclip and it's in the upper right next to the three vertical dots that stand in for a menu button.
Depends on which text messaging application you're using, but once you've got the application open you should see paperclip somewhere on the screen, like below you'll see it on the bottom left hand side. In that one once I pressed it, it opened up to a camera image at the bottom and also gives you a choice of going to your folders or jpegs or other images that you already have stored.