What are all the applications I need to create an Android app?

I think there is like something called Eclipse, and a SDK something, but I have no idea. Can someone tell me what I need to download and a direct link where I can do that? I am on Windows 7.|||The better think is following the android book, you can get the book from this site http://android-codes-examples.blogspot.com/2011/04/android-books-you-can-download-android.html