On reflection - the easiest way to handle this is to give contributors a template for submissions... all the editor needs to do is paste it to the website.
It sounds like you want an online pre-publication page - and vetted articles make it to a monthly publication (perhaps emailed, perhaps print) which gets archived.
This is how a lot of professional blogs get handled. See Bruce Schneier for eg - his articles build over the month then a newsletter is posted out at the end. His is minimal, but getting picture submissions - the one that didn't get away - is a function that can be added. Entering articles as comment would be easy.
You can use one of the online services to host the wiki or blog or what you end up with, or you can run a server yourself.