What are some things to consider when starting a new business?

Me and my girlfriend and her sister want to open up a bar/club in our area. We've taken into consideration many factors; licensing, zoning laws, location, etc. However, we want to be as prepared as possible, so can anyone help us brainstorm what else we should consider? Please be as specific and detailed in your answers as possible, and remember, this is for a bar. If there is anything specific to this type of business we should consider, please let us know. Thank you.