Look here -
http://www.blood.co.uk/special-appeal/
Now you can go and find out your blood group and then donate.
This thread has prompted me to book my first ever appointment to donate blood, next week at 18:30. Any tips for someone doing it for the first time? Should I take anything with me for afterward as I'll no doubt feel a bit weak after donating? My wife is taking me, so I don't have to drive. What should I expect with the donation process?
Of the course of your donation the process will change, I've only been doing it for ~5 years and it's slightly different.
Nowadays you go in see the person at the front then you either give them a pre-filled form (if you get one posted) or she gives one to you to fill in.
You then sit down, have a pint of water. After a while you are called to a desk where a nurse will quickly run through the important bits of the form (been out of the country etc etc) then you have a needle p-rick (got starred out for some reason) in your finger (this is more painful the the actual donation so once you realise how minor this is you'll not be scared anymore), a tiny bit of blood is then dropped into a copper solution which is a test of iron (if your blood sinks to the bottom in a set time you have enough iron). Most healthy people will pass this test with ease. If for whatever reason you don't pass they take a slightly larger sample of blood and run it through a machine so you get a free Heamoglobin test. You can be unfit to give blood but still not be aneamic so you don't need to worry unless they also say you should see a doctor
Even if that is the case you'll be better of in the long run knowing this.
You then go to a different seating area before being called up for the proper donation bit, where you basically just lay down until you can go to the food table. I always look at the needle going in to make sure they do it right (even though I wouldn't know if they did do it wrong lol). You have to clench and un-clench your fist every so often to keep the flow nice. They also recommend clenching your buttocks nowadays although this is not something I have ever done although as a first timer you want to be sure you don't embarrass yourself by passing out so may as well do it.
When they are done you will be told to squeeze the paper on your arm, this is an imperative process to stop any bruising. All bruising is, is blood leaking from your vein into the tissue of your arm, squeeze hard and you stop this happening, don't and you'll not stop the vein from leaking and you'll look silly the next day with a bruise.
First time don't have a hot drink, and make sure you have at least two packs of food and a couple of the cold squash they have. Then book an appointment for the next session.
Simples