The PTA and the Governing Body are quite different. The PTA have a fund raising role (usually for extras for the school, not textbooks) and a social role.
School Governors are there to do the following:-
1 To Provide a Strategic View 2 To Act as a Critical Friend 3 To Ensure Accountability
School Governors do not run the school; they are there to take an overview and see that it delivers.
Being a Governor varies slightly from school to school. The main thing is time and commitment. You should think of the Governor meetings as meetings that you must attend and arrange your social/work life around them. You should attend the training sessions that your Local Authority provides.
School Governors are the biggest volunteer organisation in the UK. We estimate that it takes up about 35hrs per year although, of course, it depends on how involved you want to be.
Governors deal with Budgets, Policies, Targets and things which are 'a step away' from the 'day to day' running of the school. Any question like 'My child doesn't ... isn't ... can't ...' is not for a Governors meeting.
Being a Governor can be extremely rewarding and interesting but for most people there is a steep learning curve before they feel that they are doing something worthwhile. As the Governing Body operates at a mainly strategic level there is a fair amount of paperwork that comes our way that at times can seem daunting.