We were just using Excel but have hired a bookkeeper who will use Quickbooks. I'd love to do it myself but there are only so many hours in a day...plus we've grown quickly and I'm feeling some security in using a professional.
I use Quickbooks for my business and I love it. They offer several versions including a free one QuickBooks Simple Start that you can download. The multiple versions make it easy to upgrade... when your business outgrows the current version.