If you are after an introductory course on bookkeeping, City East Community College has an Accounting for Non-Accountants course available.
You can fill in an enquiry form and the college will alert you when the next course is due to start.
CityEast Community College has another short course due to start soon, which covers MYOB (Sat 18th June - 25th June). If you are interested in this course, fill in the green enquiry form after clicking on the link.
This course costs around $295.
If you don't mind going into the city, WEA Sydney has an Accounting for Non-Accountants course or several MYOB courses starting in June.
You could also consider taking an online course, if you need to start straight away and you don't mind learning from home. Cengage, for example, has a longer Statement of Attainment in Financial Services (Bookkeeping) as well as Certificate and Diploma level courses.