My current setup involves the following:
– Mountain Lion OSX10.8.4
– IntelliJ IDEA 12.1.4
– JDK1.6.0_51
Update Aug 23, 2013:
– IntelliJ IDEA 130.1619 (Cardea Preview) – Community Edition – Early Access Program (EAP). See screenshot below under Notes.

My main reference is http://www.java-javafx.com/2013/02/first-android-application-on.html

Step 1. Get the JDK

According to the Android Developer System Requirements http://developer.android.com/sdk/index.html, we should have JDK6 (JRE alone is not sufficient).

UPDATE Oct 16, 2013: On IntelliJ’s project settings, you can choose either jdk6 or jdk7. There is no need to remove jdk7 if you need it in other java projects.
jdk6or7.png

1a. Install JDK6 from Apple

https://developer.apple.com/downloads/index.action.

java_download_from_apple.png

  1. Search for “Java”

  2. I downloaded Java for OS X 2013-004 Developer Package (java_for_os_x_2013004_dp__11m4509.dmg)

1b. If you want to remove JDK7, then follow the steps below.

To find traces of JDK installed on my machine.

/System/Library/Java/JavaVirtualMachines
/Library/Java/JavaVirtualMachines

To complicate, I installed Oracle’s JDK7. So to start on a clean slate, I decided to uninstall JDK7 and stick with JDK6.

Removes Java Applet Plugin from System Preferences
http://www.java.com/en/download/help/mac_uninstall_java.xml

cd /Library/Internet\ Plug-Ins/
sudo rm JavaAppletPlugin.plugin

Removes traces of jdk7
http://docs.oracle.com/javase/7/docs/webnotes/install/mac/mac-jdk.html

cd /System/Library/Java/JavaVirtualMachines
sudo rm -rf jdk1.7.0_06.jdk

Step 2. Android SDK

Download the android-sdk for MacOSX http://developer.android.com/sdk/index.html
android_sdk_macosx_download.png

Once download is complete, I transferred android-sdk-macosx to /Developer

/Developer/android-sdk-macosx% l
total 8
-rw-r-----   1 rupert  staff   1.1K 29 Jul 16:00 SDK Readme.txt
drwxr-x---   2 rupert  staff    68B 29 Jul 16:00 add-ons/
drwxr-x---   2 rupert  staff    68B 29 Jul 16:00 platforms/
drwxr-x---  36 rupert  staff   1.2K 21 Aug 13:29 tools/

Step 3. Install Android Platform from the Android-SDK-Manager

Launch android-sdk-manager from the tools directory

/Developer/android-sdk-macosx% cd tools
/Developer/android-sdk-macosx/tools% ./android

Select the packages

android-sdk-manager.png

Step 4. Add Android SDK to your project

  1. Open Idea

configure.png

  1. Click on your project and navigate to > Project Defaults > Project Structure

project_structure_android_sdk.png

  1. Click on “+” > “Android SDK”.
  2. Specify android-sdk-macosx path (/Developers/android-sdk-macosx). Click “Choose”.
  3. Shows a drop down list which displays “Java SDK:” and “Build target”. Choose which target you want to support.

android-sdk-select.png

  1. Hit “OK”

Step 4. Create a new Android Project

  1. From the Welcome screen, click on “Create New Project”

configure.png

  1. Specify the following settings:

new_project.png

a. Select “Application Module”
b. In “Project name:”, specify “hello_world”
c. In “Project SDK:”, choose “Android 4.3 Platform (java version “1.x.x”)”

Hit “Next”

Important:
Take this time to load as much SDKs by clicking on “New” > Choose directory (/Developer/android-sdk-macosx)
multiple_sdks.png

  1. In Project properties, you can create an “Android Virtual Device” from the avd manager.
    avd.png

Hit “Finish”.

  1. Project Loads
    hello_world.png

  2. Hit the play button to run the adb. It will launch the emulator. Be patient.
    play.png

Notes

  1. http://confluence.jetbrains.com/display/IDEADEV/IDEA+13+EAP

Idea13-EAP (Community Edition) is better in terms of the Layout Designer.
idea13.png

  1. http://blogs.jetbrains.com/idea/2013/05/intellij-idea-and-android-studio-faq/