If you`re looking for a `calculator` of sorts to plug in some estimations to find startup money, this basic calculator from BusinessKnowHow.net may help provide some insight.
Startup Cost Calculator: http://www.businessknowhow.net/bkh/startup.htm
It will help you think about line item costs and provide a total number for you.
I`m surprised SUN doesn`t have something like this in one of it`s topic areas.
As for free accounting software, the QuickBooks link provided is a great resource as well as Microsoft Office Accounting Express (free). http://www.microsoft.com/smallbusiness/products/office/accounting/default.aspx#overview
I hope these are a start to answering your business venture questions.