Questions about sponsoring your parents

Hi,

I came to Canada as a landed immigrant (spouse sponsorship) in December 2006. I just want to know if I can sponsor my parents now? How long do I have to stay till I will be able to sponsor them? I have a permanent job with American Express and our family income is more than 75,000. Just want to know if I can sponsor for my parents now, or do i have to wait for a certain period of time? Also if I can, what kind of documents do i need to provide? And last but not least, if I can't sponsor will my wife (who is a Canadian Citizen) be able to sponsor for my parents?

I know that's a lot of questions, but I would really appreciate it if someone will take their precious time to answer these questions. Thank you!!!!