You should watch this video on Youtube as cvnmcvnmcvnm1234 has posted annotations to it which I don’t think appear here. Great set of tips to go along with hectic gameplay. Via this post on Reddit. If you’re new to Team Fortress 2 then you’ll want to visit NewToTF2!
Here’s a great scout gameplay commentary that appeared on Pixelenemy so some of you may have seen it already.
Here’s a big list of video guides to TF2 for your viewing pleasure. So much! Brain Overload!