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You'll get lots of opinions and answers to your questions. I'll try to keep mine generic. In your situation, you might want to look at a CMS or Content Management System, which will allow multiple people to maintain their own sections of a website, without having to be technical.
If you do have technical people available, and want to collaborate, there are quite a few collaboration softwares available, a common one is Contribute from macromedia.
Beyond that, just dive in, get wet, make mistakes, and read lots of tutorials. With that much experience in the tech world, you should have no trouble picking up something as easy as webmastering.
Im with txbakers on the CMS suggestion for 2 reasons. 1st it speeds up development by allowing different departments to manage their own areas, 2nd you can control just what level of access you allow department personel to have. From our point of view I'm pretty sure you don't want everyone to have high access levels. Just give them enough to edit or alter their files and anything above that level has to be done by the webmaste (you).
In terms of choosing a CMS, that can be a very difficult descision. My advice is to search for suitable apps and install them all. Give them a test period to evaluate them (not live) and then reach a descision. Base the choice on the feelings of everyone involved, that way you can be fairly sure that everyone will be able to be productive on it.
Most CMS's will also allow for distributed content authoring and approval through some sort of workflow mechanism.
I of course have my opinions about which CMS is the best but rather than poison you with my predisposed opinion. Find out what you really believe the requirements to be. You can get a start on finding a good CMS at cmsmatrix. Just google it and you will find the web site.
That site compares CMS systems. I think both commercial and open source. I suggest open source.
You can get an idea of the requirements you could be asking the rest of the users about from here.