As long as you did not submit the file to the IRS, you can edit the file to add the W2s whenever you receive them.
For planning purposes, you could add the information that you know about the other jobs so that you can estimate the taxes that you will have to pay. Then verify and correct the information when you have the W2 in hand. You can enter the information that you have for income from your paystubs, etc. When the Turbo Tax calculates many of the questions it asks will depend on the income that it calculates that you are reporting so it is good to have the income entered quite accurately to give a fairly accurate final tax refund or amount to be paid.
