I took over Troop Treasurer becuase the last person was just spread too thin with other activities. The last treasurer used some program that I've never heard of, and subsequently, I couldn't open...
With paper reciepts and statements I was able to account for 99% of all the transactions and started my books with a clean slate.
I use Excel... everyone has it and it is easy to use. I know how to use Quickbooks, Peachtree, and some other programs from my college accounting classes, but I believe in the KISS method... Keep It Simple Scouters!
Something to keep in mind is the person that will come after you... they will need to be able to use whatever you are using and understand it.
I have a few sheets that I use: an account ledger (a rolling debit/credit for everything throughout the year), scout accounts, a sheet for each campout/event, and even the Troop Treasurer's monthly committee report (in/outflows, etc...)
Also, I keep a paper copy of everything, as I know how computers can crash with impecable timing. And, each time I finish working on the ledger, I save it as a different file (just change the date at the end of the file name)... that way if I discover a mistake a month or two down the road, I can recover from a previous one as needed.
Also, make sure you periodically bounce your statements off the bank's (or whoever keeps your money) statements... they should jive to the penny.
My two cents ;P
Yours in scouting,
Colonial Virginia Council