Does box 52 on my T4 already include my RRSP contributions made through my employer? or do I still need to report these separately with slips in the RRSP section?

Box 52 on the T4 includes the employers contributions to a pension fund but not the employees. You will include your own receipts under the RRSP tab and RRSP Profile area of Turbo Tax.

Where specfically?

As Terry said, Box 52 on the T4. It's labeled as "Pension Adjustment".