I requested the removal of conditions on my Green Card (I-751), what do I do during the wait period?
The I-751 form and accompanying documents are mailed to the USCIS Service Center that serves your geographical area. (Use certified mail or priority mail with delivery confirmation, and write "Attention:I-751 petition to remove conditions of status" on the envelope under the address.) You must mail the package to the address as directed (for the type of form) by the USCIS Service Center you are filing at.
You will receive a notice of receipt for the form stating that "Your alien card is extended one year - employment and travel authorized". Keep the receipt with your green card. If you are not approved within a year, you will want to make an InfoPass appointment to go to your Local Office and request an I-551 stamp in your passport. This does happen as it sometimes it takes over a year to be approved. After your NOA extension expires, this is your only evidence of legal status which you are required to have by law.
Cases can sometimes take more than a year, but that's rare. Local Offices will not give an I-551 stamp if you have another type of evidence of status (ie, expired Green Card extension letter). You may or may not be called for an interview after you submit this form.
Simply follow the instructions that you receive from USCIS and don't worry too much about other peoples' situations. Yours is the one that counts for you. If you are selected for an interview, it will be at your local USCIS office, not at the service center. Most typically, you have already had a biometrics appointment before your notice of approval, and your new Green Card will be mailed to you.
You should follow all directions received from USCIS. Once you have removed the conditions on your green card, it should be renewed every 10 years. An exception being if you become a citizen before you need to renew your Green Card.