How do I set up my contributions for the plan?

From your paycheque 

When you enroll in the plan, you will specify the amount that you would like to be deducted from your paycheque every cycle. If your employer is offering payroll contribution matching, you can still contribute beyond your employer's matching threshold. If the terms of the collective agreement with your employer limits your payroll contributions, you can still contribute directly from your bank account. 

From your bank account 

You can select to make monthly contributions that are automatically deducted from your bank account. You can also take advantage of the plan's unique auto-escalation feature, which lets you commit in advance to a scheduled series of contribution increases to keep up with annual inflation rates and your income growth. If you've joined the plan through a participating employer, this is an opportunity for you to contribute more via your bank account. Additional contributions can be made by initiating a one-time lump sum contribution or transferring funds from an existing TFSA or RRSP.