Setting up your GoDaddy domain with Podpage takes some steps, but is overall fairly simple. Here are some steps, and there's a video at the end:
1) Log into GoDaddy
Log into your GoDaddy account and find the link to Manage Domains, or click here: https://dcc.godaddy.com/domains/
2) Find the domain your want to set up in the list, click the three dots, and select "Manage DNS"

Take takes you to a DNS Management page that should look something like this

3) Turn OFF all forwarding
Scroll down to "Forwarding" and make sure your domain name isn't being forwarded anywhere.
4) Find the CNAME section
Most likely there will be some CNAMEs created already for your domain. If you are setting up www.yourdomain.com, look for a CNAME that has www in the name column.

If you see one, click the pencil icon. If you don't, scroll down and click ADD.
5) Enter the Podpage DNS
Follow the instructions from this article to finish setup: