Mothers are encouraged to raise money by holding coffee mornings, clothes-swapping parties and girlie nights in. They are also urged to take part in one of the 12 pyjama-clad 5km runs taking place throughout the UK.
The charity is hoping more than 100,000 mothers will take part in the week-long campaign and raise more than £600,000. About 80,000 women took part in last year's event, raising £280,000.
Save the Children has been named as partner for transport company FirstGroup's £1m campaign to support underprivileged children in the UK. The money will go towards improving children's standards of living and helping the charity develop partnerships in the poorest parts of the country. The first event will be the First Monster 120km team duathlon challenge at Loch Ness in Scotland.
Mercy Corps, the international development charity, will stage a car rally from London to Mongolia with the aim of raising £250,000. More than 200 cars will attempt the 10,000-mile journey from London's Hyde Park to Ulan Bator, the Mongolian capital.
St John Cymru will knock on thousands of doors in the Swansea area over the next few weeks to ask people to support its £1m Ambulance Appeal. The charity aims to collect enough to upgrade its fleet of 100 ambulances.