You should learn some basics about computer recording first, no offense. It is not just about using Cubase and reading manual, you have to know about whole thing.
Anyway, first you have to switch to Audigy Asio driver. It will switch your card to 48Khz and you will get option to enable direct monitoring on the same page.
Now you can apply it. One of the things you also could do is to enable 24 bit recording in settings. Then at the left in the arrangment, activate inspector so you can overview channel without opening mixer. Now check what soundcard in is selected for chosen track, because your guitar is mono, in mono track, only left in will work properly, and in stereo track you will hear only left side.
As you did not explained what are you actually using for recording guitar: If it is some kind of guitar processor, it should go to the line in of the audigy, be sure that you can hear yourself when playing. You should hear guitar even if there is no monitoring enabled, and YOU SHOULD NOT activate it, because you wil hear guitar doubled, original sound, and monitored sound.
If you are using guitar directly into card and want to use some kind of software ampsim, you should plug it into proper DI box and then into mic in. In case you don't have DI box, use some kind of guitar processor with all effects turned off. Then you should mute soundcard in using system mixer (not cubase mixer) open plugin, and enable monitoring on track to hear your guitar, disable after playing to hear recorded guitar.
If you don't have a proper DI guitar will sound probably really bad but for the price you have paid for the cubase and audigy...Who can argue?
In related news, I can't get Cubase SX to play back my MIDI. Just like your audio. It recognizes it but doesn't record or play back. Good luck to us both.
No offense, but what you say does not makes much sense. Midi is a system of communication between devices, not devices itself. In program like cubase you have midi channels that can send informations to:
- Midi out of the soundcard and then to external equipment
- VSTi's in virtual rack
- Soundfont banks in Audigy's own personal soundfont sampler
- Windows synthesizer
- VST effects that could be controled by midi
So when you say "Midi does not work" what you really want to say? What is not working?