While older versions of iOS required you to email pictures and videos using the Photos app, or more recently, tediously copy and paste them into a Mail app email, iOS 6 adds the ability to insert them directly into an email. If you've ever had times where you started typing out an email and then had to close it out in order to copy and paste an image from the Photos app, you'll understand why this feature was much needed.
Now, the bad news is that instead of a simple, multipurpose attachment icon in plain site, Apple is only letting you attach pictures and emails (not documents or anything else), and they've hidden it away in the already jam-packed editing popover. Still, better to have than have not, so here's how it works...
Launch the Mail app on your iPhone or iPad.
Tap on the Compose button in the bottom right hand corner just as you normally would to send an email.
Fill out the sender info, subject, and body just as you would for a normal email.
Now double tap where you'd like to insert the image.
You'll see a menu come up. Tap the arrow to the right of the menu to view more options.
Here you'll see the option to Insert Photo or Video. Tap on it.
You'll be taken to your Photos so you can select the image you'd like to insert. Find it and select it.
You'll see a Preview of the image. Just tap on Choose to confirm it's the right one.
The image will automatically be inserted into your email.
Once you're done filling out your email, just tap the Send button in the upper right hand corner and your email, along with your image, will be on its way!
You can insert as many images into an email as you'd like but just keep in mind some email clients have a limit on the email size someone can receive so we'd recommend keeping it to under 5 images or so unless they're small.