You are correct, you do NOT enter billing information. 

Just follow the steps outlined int he Account Creation Guide (http://www.google.com/support/grants/bin/static.py?page=guide.cs&guide=1066269) and then submit your account for review. You will continue to get the "Billing Prompt" until after after the Grants team has approved the account and activated it.

If you run in to any issues, feel free to reach out.

All the best,

Robert