The question, "Now what do I do?" soon follows after notification that a grant has been successful.
You will need to undertake certain tasks:
If you have been contacted directly by the funding body, the Research Grants Office should be notified of success (acceptance of offer).
With many of the larger funding schemes, the Research Grants Office will receive results directly from the funding body, and will inform the researcher, either by an email to the Research Announcements list or directly to individuals.