Some questions regarding employment law, Eng

Dear forum members,

As I am using 2011 books I would like to check whether some figures are changed in new books. So my questions are:

1. How much is the national minimum wage for a 22-year old or older person per hour?
2. When calculating compensation for unfair dismissal how much is the week’s pay?
3. There are ordinary and additional maternity leaves, how many weeks are for each of them. As I know there are total 52 weeks, 39 weeks paid and the rest unpaid but it is unclear whether these 39 weeks are only for ordinary leave and the remaining 13 weeks for additional leave.

Thanks a lot in advance,
Best wishes,
Tammi