I'm here, I'm here! CQMS is a position AND also is a section. As was stated earlier, the position takes over when the CSM is away. It can be either a WO, or Sgt, and sometimes there can be a Cpl as acting CQMS, however they don't get to be the CSM fill in, and is only on a temp occasion. The CQMS section is basically the company stores, the platoon IC is the actual CQMS, and you work directly under them. The section is also referred to as the CQ. This is where I am currently. If you are posted into a good CQ section it can be one of the best postings you can wish for. You get to mingle with everyone in the company and get noticed quicker than other sections (depending on what coy you are in).
To get into a CQ you need to have yourself squared away pretty tight, or else you'll get chewed up and spit out fast. Keeping on top of things is the best route to go, and being organized is key.
As for the OP, depending on which base you go to there are many different positions available. You could dish out lubricants, clothing, coy stores, you could work in a decontamination section or repair and disposal. Pretty much each unit has a supply tech attached to it to get them the kit they need to do their job. Supply work in a first line unit (PPCLI, RCR, RCD) is different from second line (Service BN's) differs from 3rd line (Base Supply). and don't forget the Depots too. There are more civie positions than CF, but you could still wind up there too. Each level of support is very different, but very much needed to get the job done. Members usually end up in a Service Bn first, take their lumps, dig in, that sort of thing, then move on to bigger and better things. Being in a Svc Bn isn't as bad as people make it out to be, so don't buy into their BS. Take it for what it's worth, work your tail off and people will notice, and you will move on. If you are useless (not saying you are, but if you were) people will notice, you will remain in a SVC Bn, and you will end up hating it as they will hold you back.
I think that pretty much sums it up. Did I miss anything?