What's it like giving bone marrow?

i've decided i am going to do this one day. i don't care about the pain, i just want to save a life. i want to be more selfless because i've never done anything to help anyone. like i never gave blood or raised money for charity etc. i'm going to start giving blood first. i just get a little nervous thinking about it. i'm not afraid of needles. i just get a weird feeling when i see all the blood coming out of me. it seems like they take a lot but i know it's for a good cause so i'm gonna do it. i know you'll just have a sore arm for a little while and maybe dizziness afterwards. but i would like to know more about bone marrow. i know it's a lot of pain but it can't be as bad as childbirth right? i think they do this at my university. would i have to miss cl and stay in bed for a few days? i already know it's a 5 inch needle they put in you..but what's the pain like when they use anesthetic? do they put you to sleep? how long do you have to wear the bandage? it would be great to hear from someone who's experienced this :) and how long does this take? and how much do they take from you?