Here are several sources for Goddard and NASA documents which are freely available on the World Wide Web.
National Advisory Committee for Aeronautics
http://naca.larc.nasa.gov/
NACA is the precursor the NASA, and this site contains some full text NACA documents from 1921-1958.
NASA Acquisition Internet Service
http://prod.nais.nasa.gov/cgi-bin/nais/index.cgi
NASA procurement information for contractors.
NASA Technical Reports Server (NTRS)
http://ntrs.nasa.gov
The NTRS collects scientific and technical information
from NASA's technical report servers and non-NASA sites.
The full text of selected NASA documents are freely
available. Many NASA documents may be ordered from
CASI (The NASA Center for Aerospace Information.)
NODIS-NASA Online Directives Information System
http://nodis3.gsfc.nasa.gov/
NASA directives (NPDs, NPGs, etc.) and links to Centers directives databases can be found here.
Outgassing data for selecting spacecraft materials online
http://outgassing.nasa.gov
Shuttle/Payload Interface Control Documents
http://www.unitedspacealliance.com/icd/
This site includes CORE/IDD, ICD, IRD and GSE ICD documents.
Software Engineering Library
http://sel.gsfc.nasa.gov/website/welcome.htm
Wallops Balloon Library
http://library.gsfc.nasa.gov/search/balloon/
The Balloon Technology database is a special collection
of materials at Wallops Flight Facility related to
the construction of scientific balloons.
