How to Buy LED Bulbs eHow.com
Determine the wattage needed. For a table lamp, you only need about 3 watts but for lighting a room you need between 7 watts and 10 watts.
Determine the beam angle that you need. LED lights do not emit light in all directions like normal lights. The narrower the beam angle the more like a spotlight the LED will appear. A 100 degree beam angle should be wide enough for most rooms and lamps.
Decide how many LED bulbs you need. If you plan to upgrade multiple lamps in your house, consider getting a multi-bulb pack to save money.
Compare prices from multiple sources. The lights can cost around $100 or more so differences in price can add up. See resources for several online dealers.
Chose the LED bulbs that are right for you and order them online or purchase them in person."