Gamestudio and lite-c are not the same thing, but you are posted in the wrong place. You want to post in lite-c programming.
Maybe a moderator would move it for you? They don't like it if you double post.

To import a sketchup model you would have to save the model and open it in MED (the free modeling prog you get with lite-c) Then save in mdl format. I do not know how easy that is with sketchup but you have to do that for every external modeling program.
The lite-c workshop is the tutorial you need, but if you are looking for a video tut I think you are out of luck.