For small setups or short outages you can use flashlights. Not LED flashlights but the older bulb flashlights with the square batteries. You can find them at Lowe's. Get several. I've done this and the batteries last for 4-5 hours.
Better options are to run CFL lights and use one of the following:
You can use a generator (although noise is a consideration when everything is silent because the power is out). If you get a cheap generator it will be noisy. You can surround it with plywood to help reduce the noise.
You can buy a "portable power" device with an outlet (walmart, harbor freight, or Amazon) but you'll need to calculate the amp hours and make sure it matches your outage time. These may provide enough uptime for just CFL lights. Lookup "power inverter calculator" to figure out the uptime.
You can buy a marine battery, a female cigarette lighter plug, and a power inverter from Walmart to plug the CFL light in to. These marine batteries will show amp hours on them but this is at 12 volts. You need to use the power inverter calculator to determine how long it will run your CFL lights (or other power items). Be sure to charge the battery to ensure it is at peak before needing it. This is the best option if you need silence and the power will be out for a while. You can also run a carbon scrubber as well but will obviously reduce total run time. I'm using this option myself very soon.