As I frantically shuffle through a year's worth of paper preparing this year's sales tax payment, I'm thinking I need to clean up my act.

First off, I'm no accountant - start talking about money things and my eyes will glaze over pretty quickly. The reality of the situation, however, is that tracking my finances is, at best, very loose right now. The simple act of writing up an invoice takes longer than it should and it not related to anything else I do. Tracking taxed, taxeable, COGS, etc . it's just getting uglier each year.

I'm just looking for something very basic that will let me enter sales and expenses when they happen, run off an invoice without having to think about it. A way to tie payments to invoices would be good, etc.

I was just informed that the state wants me to file sales tax quarterly now rather than annually, so I'm going to have to get my STUFF together if I'm going to make that happen.

I have no experience with anything.
I see very mixed reports about Quicken and Quickbooks both -
Any Open Source stuff out there that would fit the bill? I'd gladly donate to an open source project than be tied to an anual update fee for Quick* software.