Ok, so I'm very new at this and don't know much so my question might sound stupid.
 
I bought a A&H ZED12FX as it came with Sonar LE and because of this I thought I could use it as an audio interface. So my question is... How would I record different instruments and vocals through the A&H as separate tracks to Sonar LE and then mix then together.
 
Apologies if this has been discussed. 

You can only record 2 things at a time, The USB output was intended to be used for a stereo board mix and play back of break music. It is not a good choice for a interface. I don't think there are even proper drivers. 
 
But it will work if you know how to record a band in parts. 
You will be mixing the tracks inside Sonar not on the board. 

The drivers are awful on this thing but a good  small board otherwise.  I use it pretty much as Cactus Music described .  I keep hoping to setup as a control surface in logic but the mac drivers are confusing .  Have not bothered attempting this with Sonar yet

An Analog mixer cannot be used as a control surface. There is no info sent from any of the controls, they are analog not digital. 
All they have done with these type of "USB" mixers is ad a very basic A/D convertor and patch it to a USB port.  $ 12 worth of hardware. 

That explains a lot.  One of my coworkers claimed this thing will work as a control surface. 

Thanks for all the replies. I understand that it cannot work as a control surface and I know it can only record 2 channels. What I don't know is do I record 2 chanels of vocal, then 2 for drums, then for guitar etc in sonar? And if so would I just save each recording separate and import it into Sonar? Will this work like that? Or would it be one track? Sorry it's a bit confusing with only the 2 channel recording.

Mono sources (like vocals, guitar) are recorded mono (=one track) and stereo sources as stereo (=two tracks).
Drums are a different beast because you usually record individual kitpieces in mono, but overheads in stereo or double mono.
 
I don't understand what you mean by "importing" the recordings to SONAR. SONAR is your recording software, and you record directly on SONARs tracks.
 
Recording a band with that setup requires a lot of trial & error I assume, and I'm not able to give specific advice.
 
 
 

Like I said, you would have to have the knowledge on how to record a song piece by piece. It is the most complicated method and not everybody can work under that type of set up. 
It would mean being limited to a 2 track drum mix. :(    Major drawback right there. 
The drummer would have to play to a click track, then each member of the band would have to overdub their part. It can be done, but plan on it taking way more time. 
Bands work best playing together. 
I would purchase something like a Tascam us1800 which gives you 14 analog inputs. $300. 
The A&H board can be used as part of a nice set up with a proper audio interface involved. 
You need a min 6 channels just for drums. The us1800 would allow the whole band to play and record together. 
 

Thanks Kalle. What I mean with importing is the ZED is setup on 2 channels with Sonar. So I thought I need to record vocals to the 2 channel setup, then save and create a new 2 channel setup and record guitar, etc etc. Then take the saved tracks and open in Sonar so they are all together. But I see this is going to be difficult and I would probably have to get another AI.
 
Thanks for the info Cactus. The Tascam looks like a good AI. How would I connect the Tascam together with the AH to make them work together?

Welcome to the forum.
Are you recording a band? If not, the AH should be sufficient for most 1-man-bands.
You record a mic or guitar using either the right or left input in SONAR, and once done with that track, go to the next track in SONAR and record your next vocal or guitar or piano, etc. That's how many of us work; my interface is only 2 channels, too.