I unpack it in "C:\Program Files\Subversion". To get the commands to work you have to add the bin to your path. In my case I add "C:\Program Files\Subversion\svn-win32-1.5.6\bin" to the path. After this I open up a command window and do the following:

mkdir subversionRepository
cd subversionRepository
svnadmin create project1

Now, in order to make Subversion work in Eclipse I add http://subclipse.tigris.org/update_1.6.x to my update sites. After downloading this I restart my Eclipse and go to Window -> Show View ->Other->SVN -> SVN Repositories.
I right click in the opened view and create a new repository location. Instead of writing a http adress in the URL window I now type "file:///C:/subversionRepository/project1". Notice the three forward slashes after "file:".

I now have an empty repository that I want to put my project into so I right click on the repository and add a new remote folder that I call trunk. Right clicking on the trunk I can now import my project by importing the folder that contains the .project file. I hit F5 to refresh the view and can see that the trunk is now filled with my first version of my project.

But I also have to associate the repository version with Eclipse, so now I right click in the Package Explorer and choose Import -> SVN -> Checkout Projects from SVN. I pick my previously created repository, click next, mark the trunk and then click finish. I get a question if I want to overwrite my previously created project with the same name and say ok. I won't need that now that I got a versioning system!

I can now finally continue my studies of the tool I was looking into.