Are you talking about using Google Apps for your domain? Google isn't a mail client; it's mail hosting.
When you set this up, you'll receive mail with a link to Google, which it looks like you may have followed the instructions. Your DNS, which you can get to in the DreamHost Panel under Domains -> Manage Domains, should have these entries:
MX 0 aspmx.l.google.com.
mail MX 0 aspmx.l.google.com.
mail CNAME ghs.google.com.