damn sam, you're actually making me work. had to come home and load up the game on the new box.

anyway, if you hover your cursor over a particular skill, it will show what the minimum stat is to raise it (like min cha =6 or something). if you put a point in that skill, next time you hover over it it'll say min cha = 9. so you have to raise your cha before you can put another point into that skill. every skill is based on a different base stat, but you can hover over each one and find what it is.