Want to improve someone's life? Fostering could be for you.

Fostering offers the chance to make a real difference in children's lives. When foster care works well - which it does for thousands of children every day - it allows some of society's most vulnerable children to enjoy the benefits of family life while they are unable to live at home for a period of time. And with a shortage of over 10,000 foster carers across the UK, it is essential for these children that more people come forward to take up the challenge.

The reasons children need foster care are as varied as the families they come from. Parents may be too ill to offer care, need some temporary support while they deal with a family crisis or have a drug or alcohol problem. They may themselves have had a difficult childhood, and struggle to understand what their own children need. Some cannot cope with the extra stress of looking after a disabled child. In some cases, children in foster care have been victims of abuse or neglect. Every set of circumstances, every child and every family is different.

So, it follows that there are many different types of foster care. Emergency foster carers may take in a child for just one night, while short-term carers look after a child for up to several months while they cannot live at home. Long-term foster carers can take a child on from an extremely young age until they become independent. Some foster carers specialise in taking in teenagers, others young mothers and their babies. Foster carers with enough room may take groups of brothers and sisters to prevent them from being split up. Others decide to look after disabled children.

There is no doubt that being a foster carer is challenging. Not everybody has the ability to take a neglected child into a strange new house and make them feel welcome, valued and safe. Day-to-day life is not always straightforward when a teenager with challenging behaviour joins the family. It is not easy to let go of a six-year-old child who's been in your care for two years.

So why do people foster? Speak to enough foster carers, and a common theme will emerge. "We took in a teenage girl because it suited our lifestyle quite well," says Elizabeth, a foster carer from London. "She was rebellious and often angry, always staying out late, disobeying us. It was difficult at first. But one evening over dinner, we were talking, laughing, and I remember thinking: 'She's actually listening to me!' And things just slowly turned around. She began fitting in better, coming home on time - she even seemed happier. It's an amazing feeling, making that change in someone's life."

This job satisfaction is one of the prime reasons people foster. Job satisfaction does not pay the bills though, so all foster carers are given an allowance. Allowances vary widely between fostering services but should, in theory at least, cover the whole cost of looking after a fostered child. On top of this, around half of the UK's foster carers get a fostering fee: money paid to recognise the foster carer's time and skills. Again, this varies enormously between fostering services and foster carers, depending on the type of fostering they do.

Before becoming a foster carer, it is a good idea to ask a lot of questions. Speak to as many fostering services in your area as possible - that is, local authorities and independent fostering providers - and ensure that their financial and practical support, training and expectations match up to your requirements. Many fostering services put on information sessions for prospective carers to go along and meet social workers and foster carers; an excellent way to get a feel for the service and what fostering entails.

Once you choose a fostering service and apply, checks will be carried out by the Criminal Records Bureau, with your permission, to ensure you have not committed an offence which would automatically exclude you from fostering. You will also be required to have a health check, to show that you do not have any major health problems.

You will be assigned a social worker who will help you to fill in a detailed application form, and you will probably be asked to attend group preparation sessions with other prospective carers. The final approval is recommended by a fostering panel: a group of people including social workers, foster carers, people who were fostered as children and representatives from the local community, such as local councillors.

It is likely to take at least six months from the time someone expresses an interest in becoming a carer to being approved, but once this happens, you are ready to take on the challenge of fostering, and to make a vital difference to the lives of some of society's most vulnerable children.

Garry Lemon is the media and communications assistant at the Fostering Network. For more information on becoming a foster carer, see www.fostering.net.