Didn't know quite where to put this, but I guess it's a freebie if you're buying the paper anyway. If you're like me and the Daily Mail isn't exactly your favourite read, your £5 voucher will cost about you about £2.50.
For the Tesco voucher, you collect two codes from the Saturday Mail and the Mail on Sunday and input on the website. It seems that later rewards require more codes.
Anyway, all the details here - https://mailrewardsclub.mailonline.co.uk/WeekendClub/