its that time of the year where i annoy every one to go donate blood if there is any way you can give back to society give a pint (500ml) of blood it will probably save someones life there is even a benefit for you that every donation is screened for STD’s and STI’s so if you caught something they will tell you
as of now i have 5 successful donations (as i do it at my college each semester)
the process is easy you go do the registration then the basic screening (answer a few yes/no questions) then do the advanced screening with the nurse/volunteer take blood pressure, temperature, check your iron level (with a little prick on the finger) answer a few more questions with the nurse and you make your final (anonymous) decision if they should use your blood with a bar-code sticker after the nurse leaves the screening room this is to keep people safe because someone may be to embarrassed to admit to sleeping with a prostitute recently to the nurse and not want there blood used (it is still tested however)
after they take you to the donation area and put you on a stretcher /bed thing they will find the blood vane for your arm mark it and clean the area with an antiseptic then tape down the tube (to your arm) and insert the needle they will collect a small amount for testing and the rest will go to the main bag after 5-15 minutes tou will be done you will have to hold a gauze pad for a few minutes and then they will take you to a recovery/observation area to make sure you feel ok (about 5-15 min) then you get all the cookies /juice/ coffee you want then you can be on your way but be forewarned take it easy for the next 12 hours as you will be short of breath easily due to the low blood level not to mention getting the munchies (you got to replace that lost protean and iron some how)
US:Red Cross
canada:Blood Services Canada
quebec: Hema Quebec
as for the rest of the world im sure there are simaler organizations (google is your friend)