Using ant basics:

http://developer.android.com/tools/projects/projects-cmdline...

http://developer.android.com/tools/building/index.html

And using the Android SDK Manager to manage packages (this assumes that the 3rd party libraries you are using are well-admined enough to have a proper Android SDK Manager add-on site, which many popular libs do have):

http://developer.android.com/sdk/exploring.html (Scroll down to 'Adding New Sites')

Is there an index somewhere that has a list of all libs that have a proper repository.xml? It would be great to have something like rubygems or cocoapods where you can search for all options you have for that problem you are facing.

Not that I know of. I agree it would be great to have a central repository of vetted quality projects, though.

Btw: Thanks for those links. I now have a working ant setup. I will now have to tweak a few things in my vim to autocompile the R file and stuff :) .