Welcome to the cove.
I posted a reply to your question in the ISO9001 list, and repeated here. Hope it helps.
The best work I can recommend is The Metrology Handbook, published by ASQ Press. It is for Metrology (aka calibration, the science of measurement) what the Juran reference work is for quality.
As for documentation, you need to keep the information on the gage blocks you use, along with the certificate number from the gage block's last calibration, and next due date. That provides the traceability information above your organization. You should become familiar with measurement uncertainty so that you know the errors involved with your calibration.
As for instructions, if you are going to do much calibration, join GIDEP
www.gidep.org I think is the website, and you can access military (e.g. USN's NA 17-20 series) which are considered validated.
Another thought, if you do a lot of internal cal, is to consider seeking accreditation down the road for your internal lab. The accreditation is to ISO/IEC 17025. There are five accrediting bodies in the U.S. that are accepted currently, so talk to all, if that is an option for you.
Also, get a subscription to Cal Lab Magazine, the leading periodical in Metrology.
www.callabmag.com
Hope this helps.
Hershal