First, get the situation under control. Often the snake will go away after biting, but if it doesn't, make sure you and your family are out of harm's way. Stay calm. Check which kind of snake it is, see if the snake is venomous.
If the snake is non-venomous, you're lucky. All you have to do is normal first aid: clean the wound, stop any bleeding, etc.
However, if the snake happens to be venomous, try to identify the snake, or at least remember how it looks like if you don't know its name. Do not wash the bite mark as this can destroy the traces necessary to find the right antidote for the snake's venom. Stop the spreading of venoms with tight bandage over the wound, and immobilise the victim. Make sure you apply enough pressure to delay the lymphatic spread but not too tight that you stop the blood flow completely. Call the emergency number in your place and let them know the details, try to get medical help immediately. If possible, describe the snake so they can bring anti-venom.
Agree with AnneP. I was told that to wrap a belt or something above the bite to reduce the flow of poison to the rest of the body. And, to also keep the person calm as much as possible because an increase in heart rate will increase the affects.
Growing up in South Africa you are taught to keep your eyes out for snakes. If a snake bites you, it is best to wrap a belt, or something around the top part of the snake. Calling for immediate helps is important, and also taking note of the type of snake. You may not have seen it but the person that is bitten might have.
Number one rule is for the victim to remain perfectly still - immobilise the limb if that is where the strike has taken place. Thank goodness for mobile phones. Even in remote areas there is an emergency number when out of range of the normal carriers.