Basically I've got Cubase LE. I'm ok on how to do the audio input (though it keeps crashing), but im interested in plugging my keboard into my computer to use in conjunction with th software. Basically, all I'm doing is using the sounds and instruments that come with it and drawing the notes in, however I would like to be able to play these in instead using a keyboard (it just makes life easier). My keyboard has got a headphones output that's the size of a jack lead connection, and I was just wondering how to plug this into my computer and how I would need to programme it in order to use the keyboard as a MIDI input in conjunction with the instruments that came programmed in the software, instead of cubase just recordin the piano sounds from my keyboard.
Any help appreciated.
Well, you'll need a MIDI cable to run from MIDI out of your keyboard to the MIDI in of your soundcard. If your keyboard does NOT have a MIDI out, then you're out of luck.

MIDI is a packet of data. So there's no workaround to make a non-MIDI keyboard work like that.

After you get that situation taken care of, then you'll simply select your Keyboard as the MIDI Input device and your soundcard's MIDI output, in Cubase. You may have to play around with the channel number or bank number.