I can't really describe the nitty gritty to you, but the basis is the same for all classes. Attempt to get to hit cap as it is the most beneficial thing to up your dps. Once you hit cap though it is no longer useful to get more. So get to 9% and then keep it there. Hit cap is actually a little over 8%, that's why people usually say go for 8. Some theory to read below:
http://vanilla-wow.wikia.com/wiki/Hit