EDIT: I do not use this program anymore, so I am not doing tech support on it. Please do no message/comment with questions as I will not answer them.
Here's the second part of my IS tutorial series!
It covers the tools and the basics of the uses vector layers. Sorry if it's somewhat vague in most aspects...there's a LOT of features to cover in IS, and a lot of them are hard to explain without actually seeing them in action
Remember, the best/easiest way to learn all this is to actually play with each tool and figure out the settings for yourself.
FYI: I love inking in vector layers. It is a godsend! For you SAI users, it's basically like the pen tool on there (or so I hear, never really used SAI