Every taxpayer gets a tax credit for the basic personal amount. Last year it was $10320, and this year it got bumped up to $10382. Essentially, any person can earn taxable income of $10382 in 2010 without paying taxes. Also, any person can earn up to $8231 in ONT without paying provincial taxes.
That being said, i believe your employer is still required to take off the basic payroll taxes such as CPP and EI. I believe the current EI rate is 1.73% for employee and as for CPP it should be 4.95%. CPP is more complicated. It depends if as a C.A you are considered self employed or employed. If you are self employed, you are required to pay both the employee and employer portion with a max capped at $4326.3, if you are not self employed, then you only have to pay your portion which is caped at $2163.15. if self employed, EI is waived.
You should be able to keep majority of your income from this position. I'd budget maybe a little bit over $300 dollars total deducted based on $5000 of income.
I hope this helps.