What does this mean?
Given: the 12/31/08 bank statement shows a beg. Balance of 38,783, receipts of 229,832, disbursements of 226,625 and an ending balance of 41,990/

So when I prepare for the bank rec. I use the ending balance of 41,990 right?

Also, when I'm not given a cash balance, how do I prepare a bank rec for the company's books?

The Bank Reconciliation is done to bring your organization's book balance into agreement with the bank balance.

To start you use the ending bank balance for the month. Being you do not know your organization's book balance you need to take out any transactions that are in the bank statement that you do not know about. For Example interest earned or any notes that were collected. Also add any deposits that are in deposit, then subtract any outstanding checks or charges that you do not know about like an automated payment that has not been recorded in your books. You should now know what your book balance was.

When you know your starting balance then you add the notes that were collected and interest earned, then subtract interest paid or other payments that have not been recoreded to your book balance by doing journal entries.