If you're interested in smart lighting, resources to help you can get overwhelming in a hurry. Generally, setup isn't a big deal, but once you have them, then what? For people who are mildly curious, here's a gentle introduction to the world of Light Bulbs You Can Boss From Your Phone: For now we'll mostly deal with the "regular" light bulbs, specifically the Philips Hue line of LED smartbulbs.
There are others from companies such as Wink and WeMo, and most of the same concepts apply to these bulbs.
Primarily you see two styles of bulbs: the "Hue" bulb which can be adjusted to a variety of colors, and the Hue Lux which is a white bulb that only has brightness adjustments. (Wink and WeMo are both white-only lights, LIFX is the other main multicolor bulb.) Most styles require a "hub", a small puck that sits on your network and allows for all the control.
You can get a hub with either the Hue or Hue Lux starter kit, a set of bulbs that includes the hub. Wink sells a hub separately, and WeMo has a hub too. One advantage to the Hue hub is that the hub is essentially free in the kit and whichever kit you decide on, both types of bulbs will work with it. This way you can start with the less expensive Lux bulbs and expand to full color later if you prefer.
Philips Hue Starter Kit.
Once you make the purchase, take the bulbs out of the box and screw them into the fixtures of your choice. I suggest one near an entrance/exit for reasons you'll see below. Beyond that perhaps consider a light you use often or a light in an area with an inconvenient switch. Once the lights are ready to go, turn on the light switches and (this is where it gets tricky) leave them on. It was very hard for me at first, after a lifetime of being told to turn the light off, but it gets easier in a hurry.
Now that you've got some lights set up and ready to go, this is where it gets fun. First install the official app to get the basic setup configured. You'll get some basic examples for setting up the lights, and with the Hue app you can add your favorites to the Notification Center widget. Then set up other recipes for combinations of lights, or brightness/color configurations you can activate at the touch of a button.
You can also use the Hue app to set up my favorite feature: geofencing lights. This one small change can make a huge difference in daily life since every time you come home, it no longer has to be to a dark house. Within the Hue app from Philips you can set a rule so that when your phone arrives home, your light comes on. And as a bonus it can come on at a brightness (and optionally, color) you specify so not only can the light be on, it can be dim so you're not blinded when you walk in the door.
There are a number of options for adjustments too: the lights can be set to brighten or dim at a particular time, so you can have a nice low light when you first wake up and have it gradually get brighter over say, 15-30 minutes so you can ease into your day. You can also have the lights automatically come on when it gets dark, so you don't end up stumbling around looking for a switch.
There's also the SyFy Sync app which I've discussed before. It's fun to watch television and have the rest of the room get involved. Right now this only works with the Sharknado films and the 12 Monkeys series, but so far it's been fun to watch TV this way.
Another fun way to use the Hue bulbs (particularly if you have color ones) is with apps that extend functionality. A popular one at my house is Ambify for iOS, since the largest concentration of Hue bulbs is in my basement, next to the nice A/V setup with big speakers hooked up to AirPlay. Ambify will listen to the music and adjust the lights accordingly. See below:
As I mentioned before, there are other ways to "run" the lights. You can set up integration with something like If This Then That, or IFTTT to make the lights change when certain things happen, according to a "recipe." You can browse Hue recipes for inspiration and even tweak existing recipes for yourself. Some of the fun ones include changing the lights according to weather conditions or sports scores. You can also set the lights to blink if you receive email from a particular address, or to turn off when your Jawbone UP goes into "sleep" mode.
If you use a Logitech Harmony remote, the current lineup includes a number of models that will include Hue lights in the actions. For example: My "Watch Movie" action now powers up the TV and receiver and puts them to the right inputs, turns on the DVD player, and dims the lights.
This is just a starting point, I know a there are a lot of people who are interested in "smart" bulbs but aren't sure what to do with them, so here are a few ideas. If you're doing something particularly cool with yours, please let me know, I'm always interested in finding another useful (or silly) thing to do with the lights I have now!