- download and install the JDK(JRE) & and add Java to system Path 

- download and extract the android SDK .zip file  and install android platform,docs etc & add    android to system path

- download  ADT (Android development Tool)

- download and extract eclipse IDE 3.5 

- Add ADT to Eclipse and restart

- Add Android SDK Path to ADT in eclipse and press apply

- (optinal) if you don't have android phone create Virtual phone using emulator

- if you have an android phone you need to use driver folder (usb folder in  SDK)

- to make sure that the device is connected open cmd and use adb command