Replying to Proper way to embed photos?

I'm trying to figure out the proper way to embed photos. Specifically, where you can click on the photo, and a new window pops up with the photo at full size. Now, It seems like whenever you embed one, it's very small, and when you click, you get a broken link.

I've always gone with the

, but that isn't working the same way.

Please, someone educate me.