need help configuring yum with gpg keys
 

Hi, I've installed yum on Mandrake 10.1 community on a home pc. It updated all the headers fine and then resolved the dependencies after some tweaking. Now I need to get the gpg keys as I have the gpgcheck on. From where can I import the keys and how exactly do I go about doing it?
Here's my yum.conf file (I think it's set up right) in case it's helpful in answering this question. I haven't set up my other repositories yet until I get this issue resolved.
Thanks for any help!
Dave
BTW, if anyone can point me to some more repo mirrors for this distro, I'd appreciate it.

[dave@255 dave]$ cat /etc/yum.conf
[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=mdk 10.1
tolerant=1
exactarch=1


[mdk-10.1-i586-main]
name=mdk 10.1 i586 main @USC
baseurl=*://mirrors.usc.edu/pub/yum-repository/mandrake/10.1/i586
gpgcheck=1

[mdk-10.1-i586-updates]
name=mdk 10.1 i586 updates @USC
baseurl=*://mirrors.usc.edu/pub/yum-repository/mandrake/updates/10.1/i586
gpgcheck=1

*There should be http here, I don't have enough posts to post a url