I hosted a domain at dreamhost.com and I changed the nameserver to amazon's nameserver so I could use it on Router 53 (the whole domain). I added a few records in order to host the site on S3. So far so good.
The next step was to set Google Apps to work with that domain, I registered and account and confirmed the domain. The next step was to set the MX records, my question is. Do I need to set the MX records at dream host? At Router 53? or at both?
Route 53 tells you the nameservers to set up at your registrar (dreamhost). Once you've done this correctly, you no longer need to make any DNS changes at your registrar. You've told dreamhost to tell the world that all DNS is controlled and configured at Route 53.
Goggle Apps tells you DNS entries to set up at Route 53.