Some people noticed that one instance of the link to volunteer for NomCom had a typo. The correct link is this:
https://datatracker.ietf.org/nomcom/volunteer
After clicking on the link, the reponse will be your Datatracker profile page, which will acknowledge that you volunteered. Note that you might have to scroll down to see it. Subsequent clicks will let you know that you have already volunteered, so if you're not sure, click again. :)
Subsequent calls for volunteers will probably include those who have already signed up, in the hope that this will encourage other people to do so (without commenting an their reasons). There will be an explicit challenge period for the community to raise issues about volunteers.