If you are planning to submit:
Please be sure all of the required paperwork and certifications (especially the “statement that the student has advanced to candidacy for a Ph.D., signed and dated by the department chairperson, graduate dean, or similar administrative official”) will be ready for the submission. Also, please make sure your organizational representative (usually, the Sponsored Research Office (SRO)) is aware of the due date to avoid missing the deadline.
DDIG solicitation (submission instructions): http://www.nsf.gov/pubs/2013/nsf13568/nsf13568.htm
DDIG Website (with program contacts): http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5234
You may also be interested in these tips from the IOS blog (note: this was originally posted for LAST YEAR’s DEADLINE. The deadline this year is Oct. 8, 2015): https://nsfiosinfocus.wordpress.com/2014/10/02/tips-for-preparing-your-ddig-application/.