Hi,
I am planning to change my name. I have couple of Concerns.

1. Whats the process of Changing my name on PR card.

2. I have US visit Visa. Do i need to inform US Embassy of the name change or do i need to keep a copy of name change certificate with me whenever i cross the border.( or is there a process to change name on my VISA).

Also please let me know if you know a lawyer in Northyork area who can attest my paper work for name change.

Thanks,

Here is a website that will walk you through to do the needful.
http://www.gov.on.ca/ont/portal/!ut/p/.cmd/cs/.ce/7_0_A/.s/7_0_252/_s.7_0_A/7_0_252/_l/en?docid=053266

After you get your name changed contact the PR card people with the name change and pay the required fees. You need to ask them for the correct procedure and the forms and the fees after the name change.
Change of name and address: https://services3.cic.gc.ca/ols/ols.do?lang=en

You will have to apply for another Passport and after you obtain your Next Passport they will cancel the old one and send it back to you for your files. It will state on the Passport that it was canceled. The Visa pages will be left in tact. They will also provide you with a new one.
After all of these formalities are completed, please inform the US Visa office with a copy of the Newspaper publication and with the name change also. Tell them about your newer Passport and the details that are in it. Your old visa will be still valid. But whenever you travel, carry both the Passports. The magnetic swipe will have all of the details for them to see and verify.

There are Immigration Help Centers that will provide you with all of the notarizing services. Please contact them. 1-800-461-2156/1-800-255-4541
Also any of the Newspapers that accept the ADs for the name change, will provide you with most or all of the details that you are seking here, and they will provide you all of this in detail. They do the name change on a daily basis, for a lot of other people all the time. So take a shot at the NewsPapers first and get the details.

You will have to change your Health Card, Driver's license, the credit cards, and any and all of the other cards that you have on person. Also inform the Income Tax (Revenue Canada) and the postal people, if you are moving or changing the address.

Hope this helps.

Freddie.
Also see if any of these applies to you:
http://www.cbs.gov.on.ca/mcbs/english/branches_offices.htm
http://www.settlement.org/sys/faqs_detail.asp?faq_id=4000185
http://www.settlement.org/sys/link_redirect.asp?doc_id=1000498
http://www.settlement.org/sys/link_redirect.asp?doc_id=1001957
http://www.cic.gc.ca/english/information/applications/prcard-lost.asp