First, read up a lot about living kidney donation (and its risks). There is a lot of information available at the home page of this site by clicking the info area at the upper left. You can also learn a lot by reading past entries here at the "forum" and at the "experiences of other living donors" section.
If you decide to continue, and do not have a particulat recipient in mind,
www.kidneyregistry.org can help match you with a recipient, or you can also read the many requests posted at the "looking for" section of this site.
Take your time and get well informed.
best wishes,
Fr. Pat