Business Analysts Handbook

There are several documents that are descrbed as Bodies of Knowledge that business analysts should be aware of.

In alphabetical order

BABOK - Business Analysts Body of Knowledge, by the IIBA

NPDBOK - New Product Developmet Body of Knowledge, by NPD Solutions

SWEBOK - Software Engineer's Body of Knowledge, by IEEE Computer Society

G2SEBoK - Guide to the Systems Engineering Body of Knowledge, by INCOSE

There is also several versions of a Project Management BOK, the main one being published by PMI.