Bibiliography and References Cited
The NSF does not provide a specific format for the references section, but they do say the following:
"Each reference must include the names of all authors (in the same sequence in which they appear in the publication), the article and journal title, book title, volume number, page numbers, and year of publication. If the document is available electronically, the website address also should be identified" (GPG Chapter II, accessed online 7/8/2011)
With regards to the URL, it is nice for the reviewer to be able to click on link within your reference cited section to find a paper you cited.
"If the proposer has a website address readily available, that information should be included in the citation, as stated above. It is not NSF's intent, however, to place an undue burden on proposers to search for the URL of every referenced publication. Therefore, inclusion of a website address is optional. A proposal that includes reference citation(s) that do not specify a URL address is not considered to be in violation of NSF proposal preparation guidelines and the proposal will still be reviewed" (GPG Chapter II, accessed online 7/8/2011).
Make sure all papers cited in your proposal are here! Make sure if you remove citations from your proposal, that you remove them from this list as well!
Lastly, do not overly cite yourself. Cite only your work that is relevant to the grant.