You can download the National Standards for 'Out of hours care' from Surestart's Childcarelink website ~
Out of Hours care
I stand ready to be corrected on this - but think that if you Childmind for under 2 hours per day or run an out of hours group eg. Rainbow guides or art club ~ you do not need to be registered with ofsted ....
CRB and all other official requirements do need to be fulfilled though !