Well your $100 monthly bill probably has at least $10 that are a flat fee every month. So let's say $90 is energy usage at $0.10 per kWh. That would be 900 kWh per month. And an average month has (30 days * 24 hours) 720 hours.
So you're averaging 1250 W every hour of every day for your entire house. Yes there's a lot of stuff off while you're gone at work or sleeping at night but while you're home and awake things add up quick.
Aquarium = 50?1210 Watts
Clock radio = 10
Coffee maker = 900?1200
Clothes washer = 350?500
Clothes dryer = 1800?5000
Dishwasher = 1200?2400 (using the drying feature greatly increases energy consumption)
Dehumidifier = 785
Electric blanket- Single/Double = 60 / 100
Fans
Ceiling = 65?175
Window = 55?250
Furnace = 750
Whole house = 240?750
Hair dryer = 1200?1875
Heater (portable) = 750?1500
Clothes iron = 1000?1800
Microwave oven = 750?1100
Personal computer
CPU - awake / asleep = 120 / 30 or less
Monitor - awake / asleep = 150 / 30 or less
Laptop = 50
Radio (stereo) = 70?400
Refrigerator (frost-free, 16 cubic feet) = 725
Televisions (color)
19" = 65?110
27" = 113
36" = 133
53"-61" Projection = 170
Flat screen = 120
Toaster = 800?1400
Toaster oven = 1225
VCR/DVD = 17?21 / 20?25
Vacuum cleaner = 1000?1440
Water heater (40 gallon) = 4500?5500
Water pump (deep well) = 250?1100
Water bed (with heater, no cover) = 120?380
http://www.eere.energy.gov/consumer/your_home/appliances/index.cfm/mytopic=10040