manly man man man

you don't really need the eyedrop tool to create a gradient. Basically the reason why they're doing that is because they want to use two of the same colours that are on the render. Anyways, to do it is simple. Select the eye dropper tool, and click on a certain part of the render that has a colour you like. Then in the bottom left side where you pick the colours, you'll see the colour you just clicked on will take up one of the spots. Now click on the little arrow thingy, to switch the positions of the two colours (so the colour you just got with the eyedropper tool goes to the back). Then click on another spot in your render with a diff colour u wanna use. Once you do that, look at the tools window on the left side, and look for either the paint bucket icon or the gradient icon. If you see the paint bucket icon, right click it and click the gradient one. If you see the gradient icon then obviously select it. Then just create your gradient. If you want the colours to be reversed, then click the arrow in the bottom left to switch the position of the two colours you selected from the render and create another gradient. Sorry for da long explanation, but it's far more simpler than it looks like. Just wanted to explain it thoroughly :P.

Cant disagree with prolar matt =P. But i dont advice u to start a photoshop career with gradients, ull hate it =P. And i dont want u to lol, here, Thisll help as a beginning man. Note that i dont take any credit for this tut and all credits go to Syn excluding that i juss posted it here =P. Here enjoy lol.