You could als consider business casual to be something you would wear to a very exclusive golf club to play a round.
I usually wear dress slacks (dockers are painfully obvious, and do not last well). Avoid cheap dark clothes, as they quickly fade after a few washes. Collars are a requirement. No "gimicky" shirts, like hawaiin or floral prints.
Good luck - it becomes one of those "know it when you see it" kind of things. And yes, a nice pair of shoes is important, as bad shoes stick out almost as bad as dockers
