I think you can get the pool sand at a pool place or WalMart. You can get different color sand from a company called carib sea. You will probably have to do a lot of rinsing with their sand though. That's why the pool sand is so easy, because you don't have to rinse it a lot.
You will also have to keep in mind that your sand will have to be airated somehow to keep it from getting pockets of deadly gasses which can leak into the water and make your fish sick or kill them. Some folks use malaysian trumpet snails to solve this problem. They burrow into the sand during the day and come out at night looking for food. You can also just stir the sand when you do tank maintenance. If your vacuum your tank, the sand will get sucked into the tube if you get it too close to the bottom. Simply hover the tube over the sand to suck up the waste.
If you don't have special lighting, I would suggest purchasing low light plants like java fern and anubias. You will have to secure your java fern to something into the tank. You can't bury enough of it to anchor it into the sand because they don't like to be buried like that, and it will die.
www.plantgeek.net can give you some ideas on low light plants for your tank.
Cory cats love sand, and sand is recommended for corys. I have gravel in my tank and corys do just fine, but the gravel can cause their barbels damage, so sand is preferred.