Would agree with xxx that the Big Red Book is very good for either service or retail, cash or credit businesses. It is very easy to handle and the reports are excellent. However for a small business, tailored excel spreadsheets can work very well and, if the business grows then you could convert to a package. It largely depends on the business. I would have clients using both BRB and Excel. ( I actually use Excel for all my own internal accounts ) It also might help to see what your accountant is using as aligning with them can save cost. If you can produce the records in a manner which saves them time, then that will invariably save you money in the long run.
(no connection with the Big Red Book)