calculating investment returns

[John Kuhn]

This is a bit off topic for this list, but I hope someone can help
anyway.  I would like to find some references on calculating investment
returns.  Web sites, source code and books would all be useful.

When I first started looking at this, I assumed it would be trivial
to calculate.  As I started calculating some examples, I quickly learned
that it is not.  In particular I am having trouble deciding how to
properly account for the use of margin debt and its effect on return.

Topics that I would like to see discussed include accounting for deposits,
withdrawals, and distributions (dividends, spin-offs).  Margin topics
should include reducing margin debt via sales vs distributions vs deposits
and increasing margin debt via purchases and interest.

I would like to calculate at least total return and internal rate of
return.

As you can probably guess, I have no accounting experience but I am
not afraid of equations or numbers.  I am looking for a detailed
discussion of the subject.

Thanks,
John