Have the newbie fill out a Membership Application form,

membership-application-09-11-14.pdf
membership-application-09-11-14.odt
membership-application-01-06-12.odt

If you have access to the receipt book, you can take 10 dollars from the newbie and signoff the treasurer line.

Don't forget to update the register.

If you have access to add users to the ACM servers, do that and signoff on the sysadmin line.

DO NOT accept applications with bad handwriting, make them fill out a new one