A render is something that has been cut out of something, look in the render section, plenty of selection to chose from. ^_^
well actually smart ass he asked how to use a render...not what one is or where to get them @boudey: make sure u save it as a .png file and if u mean the black around an effect C4D render then there's nothing u can really do except change the blend mode to Linear Dodge or something
This question should be posted in the offtopic question. Didnt you read the pretext on the new thread page?
photoshop or fireworks work. you use renders in websites and stuff so the images don't look copied or stuff. you add the to your own background which in cases makes the renders look better