Where can I find info on the mechanix of trading ? ie most of the examples I've seen show buying a stock at the offer...this doesn't work in real life. Also, they are always able to sell at the ask they put in their example; this also doesn't work in real life. I have only used one on line trading source "Smith Barney" and could not place a "trailing" (?) order.... it was up to me to watch it... can't be done ! I don't know any of the terms used to describe what I would like to do; where can I find out ?