No expert, but I learned a lot setting up our new acquarium last year. If I could change one thing I would not get an undergravel filter again. Try to start some plants first if you have the patience. Don't add any fish for a long time; wait until the plants are established and there is enough bacetria in the tank. You can buy kits to test the water quality. Change the water (20%) every 2-3 weeks, and don't overfeed the fish.
Rule of thumb - tank can hold one inch of fish for each gallon of tank, but I would be conservative with that. Also check to see which fish are compatible. You don't want some fish eating all your other expensive fish.
I assume you are going freshwater tropical, so I would suggest trying one of these set-ups:
1) "Amazon" tank - tetras, angel fish, corys, rams
2) "African" tank - cichlids - need lots of rocks and are very territorial; need more space, but the Calgary water is perfect for them
http://www.aquaria.info/index.php
http://www.aquaria.info/modules.php?op=mod...&catid=&topic=9
http://www.fishprofiles.com/
http://www.aquarank.com/
http://www.cichlid-forum.com/index.php
In Calgary, try:
Pisces - NE Calgary
Downtown - big shop near the River and Cecil Hotel - I forget the name
Big Al's - Heritage and MacLeod
PetLand & Petcetera
17th Ave SE - shop specializing in African cichlids
Books:
A Practical Guide to Setting Up Your Tropical Freshwater Aquarium
by Gina Sandford (Author)