Next year me and a friend are planning to travel the states for 3 months which I believe we are allowed to under the ESTA. After we have travelled the states finishing in Seattle we plan to head to Vancouver then Calgary and fly home. I am a little confused as to what Visa I need for the US and Canada, I read to use the VWP you have to be flying out from a US port? Or have a ticket to prove you are leaving the country prior to arrival? If we are driving or bus/train we wouldn't book this in advance as you would a plane ticket say from USA to Vancouver.
Any advice would be appreciated.
As far as I know you should be fine flying out of Canadian airport and they rarely check your plane ticket out of the country upon arrival anyway.
It's important to notice though that the 90 days include visits to Canada or Mexico and neighbouring islands. So if you spend 90 days, go into Canada and then back into the USA, that would not be an option. But spend ALL your days in Canada after those 90 days should be fine, the way I read it.
By the way: buying a return ticket in the first place works out cheaper than buying two single tickets, if that is what you would want.
Thanks for the information Michael, il have a more in depth look into it closer to the time!