Application Fundamentals : http://developer.android.com/guide/topics/fundamentals.html
Instructions for developing in Eclipse : http://developer.android.com/guide/developing/eclipse-adt.html
Hello World Tutorial for Android : http://developer.android.com/resources/tutorials/hello-world.html
Android video tutorial and tips: http://developer.android.com/videos/index.html#v=opZ69P-0Jbc
(Please add more links/videos if you can)
Hack-a-day Android Development 101 series (6 parts, from Hello World to the Market):
http://hackaday.com/2010/07/15/android-dev-101-%E2%80%93-part-1hello-world/
Oreilly Labs Open Manuscript:
http://programming-android.labs.oreilly.com/?goback=.gde_86481_member_25898837
Commonsware (have to pay for this one, but very comprehensive - you get a lot of stuff for $40 and it is updated regularly as the technology evolves):