You will get work authorization as part of your green card approval when your green card is approved (usually at the interview) about 4-6 months after you submit the petitions. However, if you want to be able to work in the interim, while the I-130/I-485 are waiting to be adjudicated, you have to submit the I-765. However, it also takes 90 days to get the employment authorization through I-765 so, depending on when you submitted the I-485, it may be that you are called in for your I-485 interview before the I-765 is adjudicated anyway, since you did not submit it at the same time as the I-485.
Answered on Oct 08th, 2013 at 1:17 PM