I assume this is your first tank? If so, I'll point you to the beginners section - in there you will find the beginners reference topics list......you'll want to have a good read of the threads about 'cycling'. This subject is very critical when you first set up your tank.
here's the link
http/www.fishforums.net/index.php?/topic/277264-beginners-resource-center/
If you have any questions, then post them back here.