Which qualification for nursey staff? uk?

It would depend on what job you would be doing at the nursery. At the very least you would need to make a full CRB disclosure, this gives the nursery details of any criminal convictions you have and confirms that you are not barred from working with children, you would also be expected to have at least a little experience of working with your chosen age group. Different nurseries also have their own requirements.

There's information on the different careers and the qualifications needed at these websites:

http://www.bbc.co.uk/schools/parents/life/you_and_...

http://www.nhscareers.nhs.uk/details/Default.aspx?...

http://www.nurseryjobs.co.uk/