There is a relatively good free program called
FrontAccounting that you install on your web hosting server. (Basic server account with most hosting company's is sufficient.)
You access your books from the web using any internet program (such as Internet Explorer).
This program has a lot of good features and should fulfill your needs if you are just using it for your internal book.
It is not as robust as a program like QuickBooks, but it worked to my satisfaction. (I used it for a non-profit company.)
Best of Luck,
Julie