Couple of videos here: -
How to deal with a hung-up tree when felling trees up to 380mm
http://www.youtube.com/watch?v=o9S7N-QjLGg
How to cross cut timber using the boring technique to prevent trapping your chainsaw
http://www.youtube.com/watch?v=N2zkp9HRckA
There's some interesting stuff later on about how chain profile and bar shape affect the characteristics of the chain, such as reducing kickback around the nose of the bar.