Installing Components...

        The Android software development kit (SDK) works on Windows, Linux, and Mac OS X. The applications you create, of course, can be deployed on any Android devices.Before you start coding, you need to install Java, an IDE, and the Android SDK.

        First you need a copy of Java. All the Android development tools require it, and programs you write will be using the Java language.It’s not enough to just have a runtime environment (JRE); you need the
full development kit. I recommend getting the latest Sun JDK SE 6.0.update from the Sun download site.1  Mac OS X users should get the latest version of Mac OS X and the JDK from the Apple website.
To verify you have the right version, run this command from your shell window. Here’s what I get when I run it:
    C:\> java -version
    java version "1.6.0_14"
    Java(TM) SE Runtime Environment (build 1.6.0_14-b08)
    Java HotSpot(TM) Client VM (build 14.0-b16, mixed mode, sharing)
You should see something similar, with version “1.6.something” or later.
         Next, you should install a Java development environment if you don’t have one already. I recommend Eclipse, because it’s free and because it’s used and supported by the Google developers who created Android.Go to the Eclipse downloads page, and pick “Eclipse IDE for Java Developers.” Download the package into a temporary directory, unpack it (usually this is just a matter of double-clicking it), and move the entire unpacked directory to a permanent location (like C:\Eclipse on Windows or /Applications/Eclipse on Mac OS X).
         Next install Android SDK.invoke the SDK Setup program. On Windows, run SDK Setup.exe. On Linux and Mac OS X, run the tools/android program, select Available Packages, put a check mark next to  packages, and click Install Selected.You need at least an android platform,android SDK platform tools to start with.I also recommend the documentation with it.It helps a lot during program writing.
         Now start eclipse and be ready to install eclipse ADT plugin.Select the Help menu and then select Install New Software... (Help> Install New Software...).

Name it Android ADT or whatever you like and key the address in the location  

https://dl-ssl.google.com/android/eclipse/ .

Alternate way is click the Archive button and set the path to your previously downloaded ADT jip file and select the package.Now click ok.

     Once the install is done, restart Eclipse.When Eclipse comes back up, you may see a few error messages because you need to tell it where the Android SDK is located.Select Window > Preferences > Android (Eclipse > Preferences on Mac OS X), and enter the SDK install directory you noted earlier.Click OK.

     Now you are ready for the android cooking.