A few thoughts on this: While Matt's images are very impressive, it is not always advisable to turn on all interior lights... or any for that matter. Just like with any other photography, you have to decide what look you want.
It is very customary to leave all lights off for home interiors, for example. My opinion on this is, if there is daylight coming in windows, why does the homeowner have all the lights on?
I think you mentioned that this is for a bar. In that case, you should arrived prepared with many kinds of
light bulbs at EXTREMELY low wattages... lower than you could possibly imagine. The reason is if you are going to do very long exposures (about 20-30 seconds sometimes) those practicals will let in a ton of light if you have 60 watt bulbs in them. Dimming sometimes helps, but it also lowers the color temperature. If you have no daylight to contend with (causing mixed light) then you probably could get away with using some dimmers and white balance accordingly. It is also imperative to bring ND gels to cover lights that you can't dim. Seriously consider scouting the location, seeing what kind of bulbs they have and then buy lower wattage bulbs accordingly.
Rent or borrow a good, solid tripod. Consider buying a hot-shoe spirit level (they're cheap).
If you use very small apertures, which you generally should to achieve long depth of field, be careful of dust in the camera. The smaller aperture will create a more prominent shadow on the sensor.
Definitely follow the advice above about bracketing, mirror lock up, remote shutter release/self timer.
Don't forget to shoot detail shots as well. It's not always about big, wide spaces.
Bring a laptop and review the images BIG at each setup to ensure everything looks good. Don't trust the camera's LCD.
It's very different from wedding photography, but fun and creative in its own way. The good news is, it's most likely not a one-shot deal. Despite some embarrassment, if it's a total disaster you can always do some more research and reshoot.