momma says you get put on a list after a few tests. then they call you when/if they find someone that needs and you are able to donate. its not frequent and it can be pretty painful.
she also mentioned that the same rules as donating blood may apply... ie: cant donate within 1 year of getting tattooed
I joined via bethematch.org. They sent me an at-home kit and I returned it and am now in the registry. If I'm ever needed they will contact me and it'll go from there.
I did a bethematch.org drive at school. It can be as simple as a swab of the mouth as a test to be on file. But as per actually donating, I think your local hospital would be a good place to start asking questions.
i know a friend who did it, i can inquire more to her if you are still really thinking about it. are you thinking of donating for a specific person? i miss you lil one <3