My girlfriend April and I rode the Icefields as part of a bigger bike tour last year. More on that here:http://urbanadventureleague.blogspot.com/2011/07/icefields-parkway.html
We really loved the Icefields, and I think you'll have a great time!
As for logistics, you can ride the whole Parkway in 2 or 3 days, but we took longer than that in order to soak up the ambiance and do things along the way. Remember there are two passes on the Parkway, Sunwapta is the northernmost and Bow the southernmost. Both are around 7,000 feet (2,100 m) in elevation, but the elevation doesn't drop below 4,000 feet at any point on the route. The Parkway is 140 miles long and only goes between Jasper and Lake Louise. Banff is about 40 miles away via the Bow River Parkway. While the ride is not as "epic" as the Icefields Pkwy. it's still a nice ride.
We took five days on the Icefields, which I thought was an appropriate amount of time, though we could have taken longer. There's places to stay about every 20-40 miles along the route. We opted to use the primitive hostels along the way. These are also spaced about 20-40 miles apart, and if one were to use them, one could make a credit card/inn-to-inn tour the whole way from Jasper to Banff. Most of these hostels are bunks only, most don't have electricity or phones (though one has internet via satellite!), nor hot water or showers. There is running water and propane heating, and a few within Banff Nat'l Park have saunas! These hostels are very popular during the summer, so you'd need to book them in advance to guarantee a spot.http://hihostels.ca/
We had no trouble with the passes, but we had already encountered many more passes in Washington and Montana, so we were ready. Even with that, the climbs are not that long, I remember the climb northward to Sunwapta was about 3 miles at 8% grade. I've heard that biking southward (Jasper to Lake Louise/Banff) is tougher but can't speak from first-hand experience.
- Stock up on supplies in the bigger towns like Jasper, Lake Louise, Banff, and Canmore, as there are few restaurants and stores on the Parkway. (There's just enough, however, so that you'll pass something daily.) Prices along the Parkway and in the towns are going to be steep!
- Take your time, stop at all the things you can stop at.
- There is a good chance you will see bears, even on the side of the highway. We saw a combined number of seven during our time on Bow River Pkwy, Icefields Pkway, and 93A.
I agree with geegee about Jasper (town and park) being calmer than Banff (town and park). Banff townsite is overrun during the summer.
Can't help you about parking, but can help you with photo inspiration.