NIST publication Guideline on Network Security Testing
http://csrc.nist.gov/publications/nistpubs/800-42/NIST-SP800-42.pdf
Try OSSTMM methodology (www.osstmm.org). It enumerates checks and tests to
perform. This could be a good start.
“Penetration Testing framework 0.24″ ,this would be a quick start for a checklist.
http://www.vulnerabilityassessment.co.uk/Penetration%20Test.html
And also you could take a look to the ISSAF (Information Systems
Security Assessment Framework) http://www.oissg.org
or OSSTM www.isecom.org they are methodologies for Security testing.
