If you have not imported your tax information using the CRA AutoFill service, you will need to enter any slips you have into your TurboTax return. Failure to do so would cause problems when CRA does it's annual "slip matching" and your entries did not coincide with what they have on file.
If you choose to enter your capital gains as one figure, you'll need to make sure you have the documentation on hand to support your claim if CRA has different information submitted to them.
