I am involved as an officer/director in about a dozen organizations
and need to develop a systematic means of tagging income & expenses.

I have seen portions of corporate expense codes that seem to use a
hierarchical system something like the Dewey Decimal method of tagging
books, and a few that seem closer to the Library of Congress/BL system
with both numbers and letters.
I would like to see 
1] several examples of such systems (see below a list of organizatinal
types), and
2] references to principles for setting them up. 
For the principles, URLs to detailed content would serve, not titles
of books or journals  because I seldom have access to a good library
other than those of the small organizations I work with.
Since ethical guidelines for non-profits now direct that budgets be
cross-walked to evaluable outcomes, perhaps some guides for how to
include this directive in the taxonomic scheme is needed to make the
principles practicable.
For the examples, if possible I would like to see examples of
accounting taxonomies for each of the kind of organizations in which I
bear responsibilities:
a religious order and a church;
a think-tank;
a low-income housing corporation;
an academy of creative scientists and technologists;
a high-tech consultancy;
a professional association;
a neighborhood service group with a shifting range of social programs;
a speakers bureau;
a volunteer coordinating and training agency;
a small construction job shop, working with independent contractors;
(just starting) a means of keeping tabs on back-office and information
jobs referred to family members still in the home countries, since
many of our participants are immigrants.
Because many participants are still learning English (and vary in
education level from  PhDs to grade-school drop-outs) the logical
principles should be clear because we will need to translate the
results.
Although the amounts of money involved are typically small, the
exchanges/contributions are grass-rootsy and important to low- and
moderate-income participants who want to track every penny. And the
range of issues seem a sweeping and surprising as life itself.
Quite a few people participate in several of the organizations at once
and want to see a coherent approach to accountability across them all.
A final note:
This task is more one of search and assembly, less of synthesis. That
(and translation) could be the subject of further work.