What do I need for my Fiancee Visa ???

Hi there I'm new at this but all you guys seem to give great advice any help is greatly appreciated
I have just got engaged to my girlfriend.I am a British citizen and my Fiancee is a Canadian,I have been living in Canada for the last 5 months just on my passport and not working.
We have been together for a year and a half ,and now I would like to go back to the UK and take her with me on a fiancee visa to get married.

I have accommodation in the way of a house my father owns and is willing to rent me cheaply.
I work as a Photographer and have a contract of work starting a week after I get back,I also have pre arranged freelance work.

Last year she tried to come to the UK on a working holiday maker but was denied as they though she was going to stay indefinitely.
I have a couple of question that any help on would be great

1.Will her refusal make it hard or have any impact on her getting a fiancee visa.

2.As i have been living on my savings for 5 months I have about 500 pounds left in my savings account how much if any savings do I need.

3.Would it be best for me to go home first and show that I am working and have accommodation or will a letter of offer for the contract of work and a contract for accommodation be enough

Thanks for any help
Alfie