I think we may need a bit more of an idea of what you have in mind for your trip in order to help in greater detail.
I have been to Canada several times, and i am in the process of immigrating.
Canada can feel a bit like little countries within a large one, because the 10 provincies and 3 territories are so different.
British Columbia is very mountainous and beautiful, with a temperature scale , not unlike that of the UK. then you have the Prairie Provincies of Alberta, Saskatchewan, and Manitoba. Alberta has huge oil reserves, and manitoba(churchill), is classed as the polar bear capital of the world, so if you wanted to go look at some fluffy white bears, that's the place to go !
The further east you have obviously Ontario, , quebec, and the atlantic provinces like Nova Scotia, where i have been a couple of times.
Whatever you decide to do , you will find the Canadian people very welcoming, and you will probably feel that things crawl along at a snails pace compared to over here !
If you are planning to go to either the extreme west (BC, ALBERTA) or the extreme east( Nova Scotia), you will, depending on which time of the year you go, get a direct flight. if looking at other provincies , you will probably have to get connecting flights via one of the London airports.
The link below, will give you an idea of peoples experiences , (good & Bad) regarding Canada.
I hope that's enough to get you started, I'm sure there will be other bouncers along to help you soon.
British Expatriate Community : British Expat Community