When you click on System Details you will get window where you can choose Selinux setup for your system. In Spacewalk Preferences you can Enable Spacewalk Configuration Management (I love this option as it gives me option to upload files from Spacewalk server to clients) and Enable Spacewalk Remote Commands (love this too as it gives me possibility to run remote commands on more than one server at time) Usually I left Spacewalk Profile set by default, but you can change this according to your needs. At the end you can change root password. Don’t forget to click on Update System Details.
In Locale window you can define your Time Zone.
Partitioning part is place where you can create your disk layout. NOTE: Size in options is defined in MB.
In GPG&SSL you should choose GPG and SSL keys you have created. I is set up by default.
Troubleshooting part I left by default usually.