Communications between the PI and grant review personnel should include all parties to the review process:
Vanderbilt University has excellent instructions for NSF No-Cost-Extension requests.
NSF publications http://www.nsf.gov/publications/
FastLane Use Fastlane to apply for NSF grants. Some NSF programs may allow the use of grants.gov, but Fastlane is genearally considered the easier application system.
NSF A Guide for Proposal Writing
Required Data Management Plan
NSF Required Data Management Plan
NSF FAQ on DMP
Data Conservancy Data Management Plan Template
Other Data Management Resources
U. Washington eScience Institute
Grants.gov You can search for all kinds of federal funding here.