How long is a piece of string?
Seriously, the best way to learn is by doing. Set yourself a target and start at the beginning. If you don't understand anything at the beginning, go back a level and so on and so forth until you learn it all.
E.G. Setting up Subversion. Set this as your target ("I want to have a Subversion repository that's accessible by HTTP and integrates with our Active Directory for credentials"), and the beginning would be with the Subversion installation instructions.
Say the installation instructions called for you to set up a Virtual Host (they do, actually). NFI what a virtual host is? Go away and find out, then come back. Next thing it wants you to enable extensions. wtf? Ok back to the Apache manual.
Actually, that's about all there is to setting up a Subversion repository, but the point still stands. If you don't have the time to do a course, it's great, and don't forget you've got awesome sites like this one to help you when you get stuck!