First, Sign Up for the Developer Preview.
You could joining the Android Wear Developers Google+ Community.
Then, you will get an email providing link of example and Android Wear Preview App
Third, you need to download Android SDK and start the emulator for Android Wear, one is Round, another is Square both 1.7’.
Connect the wear emulator with the Android Wear Preview app, then your android device notifications will be shown in the emulator screen.
Android Wear extends the Android platform to a new generation of wearable devices.
Small, powerful devices, worn on the body. Useful information when you need it most. Intelligent answers to spoken questions. Tools to help reach fitness goals. Your key to a multiscreen world.
There’s a wear launcher about 3.8MB,
and another Wear Preview App apk (named Android_Wear_Beta.apk, 600+KB) for those incompatible andriod devices.
The Android Wear Preview app is compatible with Android 4.3 and higher and is not available for the Android emulator.