There are several places (websites) that will sell you stock video footage; most of them are pretty good, but one of the most consistently great outlets I’ve seen is Revo Stock. This is a great source for stock footage (a very impressive amount in HD), production music & sound effects, and several pre-made After Effects projects that all you have to do is add in your own text and video for a good finished piece! It’s a great place for one-stop-shopping.
One great thing that they offer is a weekly freebie; this is usually a cool video clip or piece of animation. Even if you don’t have an immediate need for it, down-load it for another time. Sign up for their weekly newsletter via email, or follow them on twitter for links to new offerings (click HERE).