The NatureBright Sun Touch Plus was the first light therapy lamp I ever owned. I bought it after my psychotic episode. Since the 'sode came about due to severe seasonal depression, my doctor pretty much ordered me to go home and buy one of these things.
It began to work right away. UPS happened to deliver it early enough in the morning that I had time to plug it in and use it for half an hour before beginning my day. After that single half hour, I already felt more "normal" than I had in months.
The NatureBright Sun Touch emits 10,000 lux of full spectrum light -- in other words, you're getting bright white light just like you get from the sun. Not only is this necessary for effective light therapy, but this also makes it useful as a task lamp for art or crafts where you need true color rendering.
Depending on what you and your doctor decide, you can use this lamp either in the morning or the evening. Many people find it helps to split their time -- by using it in the morning for half an hour, they start their day with more energy than they usually have in the winter. Using it in the evening helps keep them from falling asleep too early, and it also maintains their mood even when it gets dark at 4:30 or 5 pm.