LED lights will typically use 10-15% of the power that equivalent incandescent lights and so are a great energy saver when boondocking. One problem a lot of people have when purchasing LED lights is the cost - as high as $16 each from a major RV chain store. You can get the same bulbs much cheaper on Ebay or Amazon if you know what to look for. The most common bulb is the bayonet style 921 bulb that looks like this

These bulbs can be replaced by three different styles of LED bulb - a panel, a pancake or a multidirectional. Fortunately they all seem to work just as well.

pancake

The critical things to check are the lumen output and the color temperature. LED lights come in a variety of colors and those colors are combined to produce the white light we are used to. However thiose colors can be combined in a variety of ways to produce a white light that is bluish or that is more yellowish. The different colors are typically called pure white for the more blue light or warm white for the more yellowish. They usualy specify a color temperature of 5-6000K for the blue light, 3-4000K for the yellowish. I personally find the bluish light to be a bit harsh for general purposes and prefer the warm white bulbs for general lighting use. These lights are basically the same color as incandescent bulbs. I have found that the bluish lights can be nice for detail work since they seem brighter and give a more intense light. I have one over my desk but all the other lights in the trailer are the warm white type. The other factor to look for is the light output specified usually as lumens. You want a bulb with over 200 lumens to give the same light output. If the lumen output isn't specified look for wattage - 3 watts is good, one watt will typically not be bright enough. If they don't specify don't buy.

There are a number of suppliers on ebay and I think they change all the time. I bought lights from 3 different suppliers  and they all arrived on time and worked really well with no problems from a total of 25 bulbs.

I bought from Bgood2010 (http://www.ebay.ca/itm/9-12-15-20-24-48-LED-5050-SMD-Car-Light-Panel-Dome-T10-Festoon-BA9S-Adapter-/331268425790?var=&hash=item7dd5aca1d1),

3c-made-in-china (http://www.ebay.ca/usr/3c-made-in-china?_trksid=p2047675.l25590)

and Amazon (http://www.amazon.com)

Just do a search for T10 warm white led