When I first got started with wood working it took me a wile to understand the difference between Crosscut saws and rip saws.
This is a quick video to show some of those differences.
Crosscut saw has teeth shaped like knives to cut the fibers they have to cross in the wood. this is achieved by the file cutting across the teeth at an angle
A rip saw has teeth that are shaped like chisels to sweep out the fibers of the wood they are running along. this is done by keeping the file at 90 degrees to the plate of the saw.
You may also want to see how to sharpen a saw here is a video on that https://www.youtube.com/watch?v=sTRpLmZqS6w
Lumber Jocks http://lumberjocks.com/Sarahsliefie