Rat Cages & Bedding
Please make sure your rat cage does not have a wire bottom! These bottoms can cause your rat to have bumble feet. Also an aquarium tank is not really recommended either because rats need lots of ventilation! Rats should have a rather large cage. But if you get your rats as babies it is harder to find bigger cages because they are still small enough to slip between the bars. If you find a cage with a wire bottom that is big enough for your rats with bars close enough together where they won't slip out and you have to have it: make sure you get something to cover the wires. A sheet of plastic (like one of those plastic cutting boards) should do the job.
A cage with horizontal bars will be much appreciated by your rats because they love to climb.
I personally recommend the Rat Starter Kit cage that's sold at PetsMart. It's huge, three stories, and comes with a good amount of stuff. Also the bars are perfectly spaced and my baby rats had no problems with them. It is 100$ but even seasoned rat owners that it's a pretty good deal. I have a picture of it on this blog.
BEDDING
Please follow this link: http://ratguide.com/care/environment/cage_bedding_litter.php
It has an easy formatted guide for what is perfect for rats and what is dangerous. Recycled paper beddings mixed with things like cotton is what I usually get and it works out just fine. I only have to clean out my cage like once a week or so and it doesn't smell at all.