so that means, if i will include my partner in my application, she will travel with me to Canada if ever I will be approved?
But still, I need to gather required docs as proof for common law partnership if i will include her in my application (such as letters, bills etc...). am i right @prpurohit?
Correct, if you include her it automatically means that both and applying for PR together. It's just that you will be a primary applicant and she will be a secondary applicant. Both of you will have to get medicals and PCC done. Secondary applicant can also help improve your score by getting ECA and giving IELTS. Both of you will receive independent PR card at the end of you get approved.
Yes you will have to provide proof of common law relationship as per this web link http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=347&top=14
The letters are not required as those are for the sponsorship process.