The financial side really is the guts of any business... and should always be kept on top of.
Unless you are considering the options of getting a bookkeeper/accountant involved, you are probably best to grab a quality piece of software (
e-conomic,
Sage,
Quickbooks,
MYOB) and a book... and just take it a step at a time.
I would suggest firstly get a Chart of Accounts setup... then get all the sales info in (no receipts), then the purchase side... and after that tackle the receipts, payments alongside the bank statements a month at a time.
Only after that is all done and reconciled (info may be missing too) then you will start to get a true idea of how the business is going. I have seen clients operate for years on a loss without realising it, but it may be profitable too. To really know you will have to take into account accruals, stock on hand etc.
Hope that helps, and if we can help further in any way please let me know.
David Toohey