I started giving blood when i was 18 and have just "returned" after having DD. It is not the nicest experience, but really doesn't hurt. I have just read in their magazine that blood stocks are becoming increasingly low, and that they need more, especially in the run up to christmas so i urge anyone who can to do it.
My DH has something in his blood (not just Carling!!) that is extra special, so he donates to help premature babies.
If you can, please go.