Many electronics drain small amounts of power when not in use. So your savings will be small, but real. An easier way to save money would be to plug things into a power strip and then turn the power strip off when not in use.
Up to thirty percent of your electrical appliance power consumption comes from keeping things on standby. Switch it off at the socket ends standby. So, yes it can.
It depends on the appliance. Modern TV's and home entertainment systems will drain some energy as long as their plugged in. Microwave ovens, coffee pots, and other small appliances that have a digital display are the same. Unplugging them can save you money, though how much is hard to gauge.
Defenitly, by doing so, you can save energy consumption. If you switch off your refrigerator for 2 hours daily, during peak hours, you can save a good amount.