There is a wide range of software systems available for small businesses. A few main players are now Xero, MYOB, and QuickBooks. We use them all, but we love Xero! (I guess that’s why we are a platinum partner.)
Why Xero? It’s super user-friendly. Has strong integration capabilities with 3rd party add-ons; and offers excellent functionality for managing invoices, expenses, bank reconciliation, payroll and financial reporting.