You will be able to print your returns as soon as the IRS/State accepts them. You will need Adobe Reader installed on your computer.
It will usually take the IRS about 48 hours maximum to accept or deny your return. You will receive an email stating the IRS either accepted or rejected your return. Check your Junk/Spam folder if you do not see the email.
After your return is accepted it will be sent to the IRS for processing. The IRS estimates about 21 days to process returns it can be longer or shorter depending upon the return and also the volume of returns they are dealing with.