Many people have booked holidays and accommodation only to find that it is not really ideally suited to their children. It may be that the accommodation has very little onsite entertainment or facilities so the children end up getting bored unless they are out somewhere. What to look for can all depend on the age of children you have and if you have children that are different ages you will need to try and find somewhere that has something for everyone.
Some holiday resorts are aimed particularly at families with kids and will offer kids clubs, swimming pools, discos and even water parks to keep the children entertained.
You will often pay more to stay at a resort that has more things for the children to do but you may actually end up saying money by not having to spend money on additional entrance fees to water parks etc.
A good holiday tour operator will be able to suggest accommodation that is suited to the age ranges and interest within your family but there is no harm in doing your own bit of research too. Work out how much you want to spend and discuss your budget with the holiday operator before looking through resorts.