The easiest way to get started in developing Android apps is to use the Eclipse IDE with android SDK and ADT plugin. There are simple instructions on the android developers site, however to confirm the steps are as follows:
1. Install Eclipse IDE, see Installing eclipse IDE
2. Download the SDK starter package.
Extract the contents and save to a directory. Your home directory is safe place where you'll be able to find it later on.
3. Download and install the ADT plugin. This is very simple in Eclipse.
a. Launch Eclipse, Click Help, Install new software.
b. Click the option to add available software and type the following in the add site field:
c. Click OK, then back in the available software list you will see Developer Tools. Selecting the check box for this will add Android DDMS and Developer Tools.
d. Click next, accept any licence agreements, then press finish. Eclipse will restart.
4. a Finally to configure the ADT plugin. Go to preferences, available under the window tool menu.
b. Select Android, and for the SDK location browse to the saved directory you have from earlier.
c. Click apply, OK.
SDK and ADT plugin for eclipse are complete.