With your eval copy, on the machine you wish to be the central admin server, launch Tools\Serial Numbers and installation. On the serial number screen, choose to add the "Central Asmin Server Option" (CASO for short) then hit install.
This will make the local server the Central Admin server. You can delegate all jobs to other servers from here after they have been added as a Managed Media server. Also, the option to store all catalogs on the Central Admin Server is available. After installing this option, you have a new tab in BE called Media Servers.
To create a Managed Media Server (MMS), you have two choices. The easiest is to go to the Media Servers tab and right click on an empty portion of the screena nd select "Install Additional Managed Media Servers". The other way is to go to each of the other media servers and run the Tools\Serial Numbers and Installation options and select fromt he list Managed Media Server (DO NOT select the Central Admin server option on the other servers, or you will have three seperate centralized servers which manage nothing but themseleves!)