Hi Larry,
You have a number of options depending upon what time of year you're thinking and how far you intend to travel in 3-5 days...
Some suggestions: the Athabasca River from Jasper to Hinton, or longer to Whitecourt. This starts in Jasper National Park in the Rockies...
The North Saskartchewan River from Abrahams Lake To Nordegg or from Rocky Mountain House to Drayton Valley.
The Bow River from Lake Louise to Banff. This one is completely within Banff National Park.
Keep in mind that snow melt and highest water is late May to late June depending upon how wet and how quickly Spring arrives.
For Resources: start with Paddle Alberta Website- lots of info there as well as store with maps, guide books, etc.
https://paddlealberta.org/
A good start for ideas is Paddle AB VP Mark Lunds
"Guide for Alberta Paddlers". He includes trips on all of the paddable water bodies in Alberta , breaking them into trips and detailing access, camping, difficulty, etc. ( Full confession: Mark Lund is a friend but I have a well marked up highlighted copy of his book on my bookshelf!)
There are Calgary Canoe Club, Bow Waters Canoe Club, Northwest Voyageurs, Ceyana Canoe Club, etc. All plan river trips amongst fellow paddlers.
I belong to Ceyana in Edmonton and we are having our AGM tonight, with planning the paddling season a high priority.
https://ceyanacanoeclub.wildapricot.org/
Some of the trips already planned are listed there.
Hope that this is helpful to you in some measure!
We look forward to you enjoying the paddling in Alberta this summer!
Bruce