Hi,

The following file attached and the link to another source may be of help.

http://www.fao.org/docrep/x5624e/x5624e05.htm

Cheers.

It depends on what you are looking for.  If you are trying to make sure it is safe you may want to start with EPA's standards.  http://water.epa.gov/scitech/drinkingwater/labcert/methods_index.cfm

You can obviosly do much more basic test but depends on the complexity and detail of your analysis.

Which variables are you interested in testing?  Some can easily be achieved through indicator organisms, whereas others involve more complex methods.  I agree with what has been written already.  There are plenty of published guidelines that are widely accepted in USGS, EPA, and SWA (safe water act) guidelines.

Please reffer the BIS 10500 Guidelines for drinking water quality and for analytical procedure go to Standard Methods (APHA)