To start with, you must find out the actually cause of water spillage causing damage to your house. A left-open faucet or a basement full of water due to heavy rains is very easy to detect and you can cope up with the situation accordingly. However, it can be a bit difficult task to find out a burst pipe which is spilling water into your house. Immediately turn off the water supply of your entire house to avoid any further water spillage and damage.
Have an assessment of the damage done by water to your house. Limited amount of damage can be repaired by yourself but if the spoils are far more than repairmen, like damaged drywalls or floors, you might have to seek professional help.
Fresh air ventilation across your house will be necessary to eliminate any foul smell. Open up your windows and doors, turn on fans and bring in box fans to get fresh air moving within your rooms. It will further help to dry out things in your house.
Arrange for a dehumidifier and run it across your house as quickly as possible. It will take out the moisture from the air and assist in drying up your house quicker, along with avoiding mould and mildew to generate in your house. Run the dehumidifier as long as your entire house if dried.
Bring in a wet/dry vacuum cleaner to clean up as much water as possible. Carpeted areas and upholstered furniture in your house will certainly need this.
If any wooden surface is affected by water, you will need to turn on fans over it and use a dehumidifier instantly to remove water from it.
You can use a detergent to clean up other surfaces damaged by water. Scrub with a brush if required.
If your ceiling tiles are spoiled by water (most probably in the basement), you have to replace them with new ones, as the damaged tiles cannot be repaired. Same is the case with insulation installed in your house.