Visit visa to canada from Ireland (London Visa Office)

Hi,
I am an Internaional student living in ireland from 3 years, would like to visit Canada.
I have been trying to find info on cic.gc.ca, but couldn't find suffienicent information regarding tourist visa.
So CAN you please help me guys.

1. How much funds do i need to show, for visit visa, ( I would like to stay for 1 week) ..?

2. I would like to apply for multiple entry (in visit visa), Is there any additional documents, do i need to show them ?

3. Is it better to apply for Single entry/Multiple Entry ?

4. My brother is a Student in Canada (Student visa), What documents of my brother do i have to show, as an proof of stay ?

And please let me know what other documents i have to show ..?

Thanks in advance.
Cheers

4.