Could someone point me to an example of table design for an accounting
related system?

I want to implement standard T-Account style accounting in my system.
Should I have a table for each account(CASH, AR, WRITEOFF, DISCOUNT,
REVENUE, et. al.)? Or should I have a single "LEDGER" table and an
"ACCOUNTTYPE" lookup table?

To link the debit/credit side of a transaction can I have a foreign key on a
field in the same table? An example (or some advice) would be most
appreciated.

Thanks,

Anthony