Assuming that your part-time business is not incorporated, you will report your business income by completing Form T2125 which replaces the old T2124 (Statement of Business Activities) and Form T2032 (Statement of Professional Activities).
This form are included in the T1 tax return package, and includes lines for you to deduct appropriate business expenses.
Your income from your job will be reported on the appropriate line on the first page of the T1 tax return in the usual way (from the information on the T4 slip that you receive from your employer).
When you're calculating your total income, however, you will add your business income and your income from your job.
If your part-time business is incorporated, you will report your business income on the T2 corporate income tax form, which you will have to complete and file in addition to the T1 personal income tax form, where you will report the income from your job.
