The two most important actions to take for snakebite: 1.) stay calm and 2.) get to a medical facility as soon as possible.
These tips may also prove helpful:
Keep the person who's been bitten as still as you can. If they've been bitten on an arm or leg, bind the affected limb on either side with splints (e.g. straight branches) to immobilise it.
For neurotoxic (cobra, mamba) and haemotoxic (boomslang, vine snake) bites, wrap a pressure bandage around the bite site and, cover the entire limb. If you don't have anything suitable to use as a bandage, apply hand pressure on the bite. This should not be done for cytotoxic bites (puffadder) however.
But don't waste time: the best chance of a good outcome is to get to a hospital for anti-venom and supportive treatment.
(Olivia Rose-Innes, Health24, March 2012)