Hi travelite_go
Good plan to get Faresavers booklets. You must walk 5-8 minutes over to the Domestic Terminal to buy them from 7-Eleven or Pharmasave.
One bus ticket is good for 90 minutes on all transit here: skytrains, bus, Seabus.
The transit system fares are built on zones. It is a 2 zone fare from the airport to Vancouver. It is a 2 zone fare from Vancouver to North Vancouver (Cap Susp Bridge, Grouse Mountain.) Effective on weekdays before 6h30 pm.
Within Vancouver, you would pay a 1 zone fare at any time. The 2 zone fares reduce to 1 zone fares on weekdays after 6h30 pm and on weekends and holidays.
So in your case, depending on the day and time of day as explained above, you might need to use one 2-zone Faresaver ticket or one 1-zone ticket each to go into Vancouver. When you use a Faresaver or a Day Pass, you do not have to pay the $5.00 surcharge to leave the airport.
So which kind of Faresavers to buy? You could buy a book of 1-zones. If you plan to stay in Vancouver for the most part, choose those. When you travel into a 2 zone area (on a weekday before 6h30) add a cash top up of $1.25 (exact change in coins) to each ticket. Again good for 90 minutes.
On the skytrain and seabus platforms, you can use credit card or cash and you will get change. On the bus you must pay exact fare in coins.
Hope this helps.