I was going to mention the guide, but I didn't want to be more of a
suckup member of the fan club than I already am.
Maybe also a little something BG2 specific, about best classes to dual and when to dual and where to spend points. I would do this, but as Ratbert said, "I'm more of an idea rat." And I only dual-classed once, and did the fighter/cleric mistake. Thus the dual-classing guide is for people like me.