The features of CM accounts are limited at this moment but we can always expect to see more features in the coming months like ability to sync ROM settings etc.
To add a CyanogenMod account on your device, go to Settings > Add account > CyanogenMod and create an account or log in with your existing account credentials. You can use the Find and Wipe functionality via: https://account.cyanogenmod.org/login.
You can read more about CM accounts at this link. If you are worried about the security of your account or your phone in-case something happens to CM servers or other scenarios, this comment made by Chris Soyars on Google+ should clarify that.
