try UNIX Academy
Try UnixAcademy.com they have plenty of training out there, but keep in mind that system administration in Linux is VERY DIFFERENT, than in Windows. I would say, it is different to a point, that there's nothing in common between them. Windows hides most of its complexity from admin, Linux in contrast, offers all of its complexity to admin. If you hope to administer Linux system, especially server, with some GUI, or web based command center, forget it. It will allow you to perform some basic operations (start/stop) and in fact it will make even more complicated, because it shows to you some candy interface, often proxying data from real configuration files. So, depending on a specific GUI "tool", someone can alter the real configuration, and the GUI will still showing to you a wrong info.
In Windows, the GUI, most of the times, has complete access to functionality and it is a main tool. In Linux, as a rule, options are too many for a GUI to account for all of them, and so GUI is an ASSISTING tool, the main tool is still a command line. Linux is too open and too broad, for one tool to handle. Beside that, most Linux clones, have their own, "in brand" solution for many things, it goes from packaging to enterprise level system managing and monitoring.
Hope it helps.