Hello everyone and thanks for you trouble.
The Arduino Yun can act as a USB host. Does that mean that from that one USB connector, it can take inputs from multiple devices?
I wanted to connect both a keyboard and mouse to the Arduino. Or is it possible to use a PS2 keyboard and mouse and tell the Linux platform that it has to take keyboard and mouse inputs from those? If the former is the case, how? If the latter, once again, any help how?
I greatly appreciate any help!
You may want to search the forum for threads about keyboards, I have seen a few posts.
To plug in two devices you will need a usb hub, the keyboard may connect automatically to the main console session, plug it in and see. The mouse will need you to define what is supposed to do since there isn't a GUI on the yun.
I'm very sorry but I didn't understand exactly what you are saying. Can you please be a little clearer? :*
Linux normally connects a keyboard to the console automatically. I don't know if linino will, try it and see. Posts in the forum about keyboards will likely help you, use the search function to find them.
what do you expect the mouse to do? there is no pointer to move and nothing to click on!
there is only one USB host connector, you can't plug two things into one connector, you need a hub to get more connections
Actually I am using an LCD with the Yun (graphical colour), so I am designing my own GUI with a special library.
Arduinoisme:
Actually I am using an LCD with the Yun (graphical colour), so I am designing my own GUI with a special library.
Now that will be a bit of a stunt. None of the I/O pins of the Yun are connected will probably not even close to the near-realtime response you would need for such a GUI... 
Ralf