Hi anil24,
If the interview goes well they will stamp your passport either the same day or within a couple days. With mine the officer that interviewed us asked if it would be okay to wait a couple days so he could organize all the papers, he was very busy that day. (I think it was because it was the end of the week and he wanted to get through everyone on his calendar).
He wrote his name on the appointment letter I had brought with me to the interview, so I could show it to security and not have to line up. He told me I could come anywhere between 8 am and 3 pm, and true to his word I had no problem getting back in and getting my passport stamped by him, took only a few minutes.
I had the actual green card mailed to me within 3 weeks after my interview date, but he told me it could be from one month to six months before receiving the card...I think they just say that because they aren't sure when the cards are sent from the other location. I received a welcome letter first and the green card a few days after the welcome letter.
He told me I was free to travel where ever I wanted as long as I either had my passport with the stamp in it, or the physical green card. I believe you will have your green card long before your holiday, and if you don't the stamp in your passport is just as good as the green card. I never travelled between my stamping and receiving my green card, but if I had I would have taken my welcome letter from the US along with my passport, just for extra peace of mind.
They said on my letter that the interview would be videotaped as well..if it was they sure have a good hiding place for the video camera because I never saw one.
Just make sure you have copies of everything along with all the original documents. The officer will ask for certain copies of your documents, but mostly just goes by the original papers you submitted. I was asked my parents names, my childrens names, my birthdate and birth place. Husband was asked his birthdate, birth place and a few general questions. Most of the questions were directed at me. It seemed to me he was just verifying the information I had put on my application. We had copies of our joint bank accounts, utility bills, 3 years tax forms, insurance, plus I had letters from his mother, his cousin, a couple friends that had visited us...all verifying that we were married and living together. Anything you have that shows you both live in the same location would be good, just make sure you make copies of everything. You might not be asked for much, I wasn't, but I would rather go with too much than have them set a new appointment and ask for more proof.
Don't forget to get a letter from your employer, stating that you are employed with that company. We aren't great at taking pictures and only had one picture of the two of us with his son, so at least with the officer we had pictures didn't mean too much.
Make at least two copies of everything, I made 3 copies...I had all my originals in one package, and made 3 separate packages, one for myself, my husband and for the officer if they asked. All your original copies will be returned to you. Two copies of everything was probably enough, but again I wasn't sure what to expect so I made sure I had enough copies for everyone!
Make sure you get there at least 30 minutes before your appointment, the worst thing that happened to us was getting through security...if I ever had to do it again I would leave my purse in the car and just carry my wallet.
Make sure you have your EAD card with you when you go to the interview, because if all goes well and you are approved the officer will ask for your EAD card, since you can not hold an EAD and a green card both. Don't forget to take your passport!!!!
Good luck, and will be waiting to hear your good news!
