The Teamship Does D&D
Here are the official treasure tables from the fourth edition Dungeon Master’s Guide. These will provide a good guideline for handing out treasure while you are the Dungeon Master. These tables are not meant to be adhered to strictly as that would be no fun. However, they do provide what would be a balanced amount of reward at each level based on number of party members and level. Feel free to and by all means get creative when devising your treasure hordes, just be sure to look at what treasure has already been dished out at this level and do your best to not throw the balance too far off.