Where do I start with a home automation setup

Here are a few basic categories of tasks that you can pursue:

1. Automate your lights to turn on and off on a schedule, remotely, or when certain conditions are triggered.
2. Set your thermostat to keep the house temperate when you're home and save energy while you're away.
3. Open your blinds during the day and shut them at night (or when it's particularly hot or cold).
4. Feed your pets on a schedule and with pre-determined amounts of food.
5. Open your garage door with voice commands.
6. Set your coffee maker to have a fresh pot ready as soon as you wake up.
7. Let a relative or friend into your home remotely with a smart doorlock

The most dead-simple way to get started with simple home automation tasks is to buy products  that are specialized for certain tasks. For some things, you can use simple timers and sensors to turn the ordinary devices you already have into smart robots from the future.

In the same vein, there are very simple remote control outlet units that allow you to press a single button anywhere in the house and turn anything connected to a power outlet on and off. Smart thermostats are a similar category of dedicated units that function a single automation purpose, rather than attempting to be a complete solution. They can be used to remotely control temperature, learn your preferences, and even intelligently disable your heat/AC while you're out and reactivate it before you get home so it never feels uncomfortable. In addition to being convenient, these can help save a lot of money on your utility bills, depending on your situation.

There are a number of standards out there that you can choose for your devices, and if you decide to go this route, the bulk of your time will probably be spent deciding which one to go with. Z-Wave for example  is world standard. 

• Software: Whether you'll be controlling your system via your desktop, smartphone, or tablet, you'll need software to run the system. You can get much of this for free either by buying dedicated devices (A Hub) or using open source software. Some solutions offer subscription packages that can range up to $99/year.
• A Hub:  Your commands are useless if your master control software can't talk to your peripherals. A hub is the brain, a box (or set of devices) that issues wireless commands to your network. More common devices are simple, self-contained units that even come with some software. You can scrape the cost of the coordinator down to $40-50 if you need to, but be careful as many cheaper, USB devices don't come with software or require that dreaded subscription.
• Sensors, switches, and peripherals: Something has to carry out your commands. Depending on what you want to automate, you may need to install wall switches, replace a door lock, or do other light maintenance. Peripheral devices can be as cheap as $40-50 per unit, but can get as pricey as a few hundred bucks.

You don't have to stick with the basic software, either. While you have one device that acts as the master control program for your network, there are always neat ways to extend your setup.