jdk >> http://www.oracle.com/technetwork/java/javase/downloads/index.html
First of all go to that link and download the JDK
Then install it.
now go to installation directory -> Program files -> java -> jdk..... -> bin.
now copy its path.
as ex : my one is -> C:\Program Files\Java\jdk1.6.0_20\bin
now go to My Computer properties -> Advanced -> Environment Variables -> path -> Edit.
past your path after ";".
as a example,
other path;C:\Program Files\Java\jdk1.6.0_16\bin
after that it looks like this,
other path;C:\Program Files\Java\jdk1.6.0_16\bin;
then ok -> ok -> apply.
now you good to proceed with java Development.