If you're updating the bathroom, you'll need to know how to install a toilet. Apply a new wax seal over the waste flange to prevent sewer gases from escaping. Put on a second bead of plumber's putty to seal any imperfections between the floor and the toilet. Place the new bowl firmly over the seal and bolt it down. Attach the tank. Cut your new tube to connect the tank to your water supply. Fill the tank and flush away.
For more on toilets, consider:
Low-Flow Toilets 101
How To: Replace a Toilet
The Complete Illustrated Guide to Unclogging a Drain