Filing I-130/I-485 for my parents.

[jagruti4]

My parents have multiple entry visitor visa. They are coming here on April'23. I was planning on filing their greencard petition after 2 to 3 months after their arrival. But, couple of recent posts has scared me on this issue. Can someone tell me - What is the logical reason of waiting for 3 months after their arrival to file a petition?
What are the potential problems they can encounter?
What precautions I can take?
I think, you can file this I-130/485 package in person to local service centre or mail it?
Can you avoid potential questions by mailing it?
I was thinking of doing all the paperwork myself, but now, considering the recent postings, I am having double thoughts. Should I hire a lawyer?
I would appreciate, experiences of anyone who has gone through this process recently.

Thanks in advance,
Jagruti

 

[detroitimmi]

The logical reason for the three month wait is the following: When somebody applies for a visitor visa that person clearly declares his/her intent not to immigrate but to visit. If that same person jumps the gun after getting into the US with a visitor and applies for I485 (through a sponsor) then that proves that the original intent was fraudulent.
You can file for I130 (IR) on your own. You won't need a lawyer, because the application is pretty simple and not as complicated as the I 140 and I 485 applications.