Looks good, planning to fly to Calgary in May next year and over a week work my way to Vancouver so any hints and tips you put up would be good...
I posted a bunch of Calgary pics and experiences
here
Maybe better if you ask some specific queries, but to go on with ....
Calgary can be a bit grim in May - they are coming out of winter and the streets are dirty with the grit they use on the snow over winter, until it rains a bit and washes it away. I wouldn't hang around there too much; its great in Summer but in May, the mountains are probably best.
Alberta road conditions
here.
Banff National park is an hour west of Calgary. Great coffee at the Wild Flour Café in Bear Street, Banff. Gondola up Sulphur Mountain from the Banff Springs Hotel.
Lake Louise is a must. Park the car at the large parking lot adjacent to the hotel and do the walk to the other end of the lake. Magnificent views the whole way. Don't stay at the Fairmont hotel - very expensive and well past its best.
Past Lake Louise take highway 93 NW to the Columbia icefields. Fantastic scenery on the way, turn off to the Peyto Lake view. At the Columbia icefields, do the walk to the glacier termination. You could carry on to Jasper, and highway 5 to re-join Highway 1, but I'd recommend going back to the Lake Louise junction and re-joining Highway 1 (Trans Canada Highway TCH). just after Field, short diversion right to Emerald Lake (pretty) and views to the Burgess Shale site, up in the mountains (world famous fossil site

)
Check road conditions and web cams in BC at
Drive BC
Back to TCH, through the Kicking Horse Canyon, onto Golden. This is a major stop-over point on the TCH. Lots of motels (the best is the Prestige Inn, on the highway); the highway doesn't go through the actual town which you might want to consider if you are stopping off. Lots of take aways on the highway, better restaurants in town. Mt Begbe is a almost local boutique beer.
After Golden, up the mountains again; glorious scenery - real avalanche country, then down to Revelstoke. Another major stopping point.
From Revelstoke you have a number of routes to Vancouver. I'd go via Highway 97 to Vernon, Kelowna and the Okanagan Valley. The latter is a major quality wine area and probably worth exploring for a couple of days. Lots of fruit grown here in Summer - May might be a bit early, but its a really nice place.
Immediately to the west you are in a rain shadow and its pretty dry, until you hit the mountains again, into Vancouver.