So I switched it over to use my own domain for blogger, added my name servers, but it hasn't switched over yet. Says it may take up to a day for the DNS to update, does that mean I have to just wait for it to update? Do I need to do anything else, or once I switch it over it publishes automatically to my website? I can just use the blogger.com to do the blog right?
you don't need nameserver change. You need to make CNAME record which require you have have DNS control over domain.
I also have a question about that. I've added some domains through cPanel... What do I need to do with the DNS? Add ftp.domain.com , cpanel.domain.com, mail.domain.com etc?? (CNAME)
If you have shared hosting and using your domain at your host with NameServer then you cant do CNAME changes. You can do it easily from domain control panel. You can set CNAME from domain registrar, to do this you have to use nameserver of your registrar and if you want to also use your cpanel with blogger then user CNAME for blogger and 'A' record for cpanel set 'A' record for www and *.domain to your server IP