Egg laying and biting

Question
Hi, Thanks for your advice. I don't know anyone with a pet budgie to ask. I have a budgie who I think is about 11 months old.I don't know the exact age as she was found but she was quite young when she was found and I have had her since December. Suddenly she has started laying eggs.The pet shop man told me to put a nest in her cage and when she lays eggs to leave the eggs there until she is no longer interested in them. Is this correct? Won't the eggs go off? My budgie is very tame and can be very affectionate, other times she bites really really hard. She'll sit on my shoulder and I'll be talking to her softly and suddenly she bites me really hard! How do you stop a budgie from biting? Why does she do this? She is very spoilt so I can't understand it.Thanks for your advice! I live in Perth, Western Australia.

Answer
What do you mean by 'go off'? They aren't explosive. ^^
I don't really know too much about eggs and breeding...my budgies never did any of that.

But I can say for the biting; perhaps she gets spooked or insecure and is biting you to let you know she is uncomfortable.