Rental Income on Main Residence

Good morning everyone,

I was just wondering if someone could help me out regarding a shared property.

Im looking at buying a property in Wollongong for me and my wife to live in, and was thinking of renting out the downstairs area of the house for 5 or so years.

I was unsure of the CGT calculations when we sell the property, how is it calculated? The ATO website is a bit vague on this.

And each year we need to declare the rent at tax time?

Thanks everyone