Well, although I'm only a participant I think the rules go something like this.
You should post in: Workbench
Title for your thread should be: Army Painter:whatever you want to call it
In your first post you should state your aim (eg. I am going to paint a WWII British Rifle Platoon. My goals are: July - 1st Section, August - HQ, September - 2nd Section, etc)
After that it's up to you how often you post, whether you want to show WIP shots, monthly updates, or just the whole thing finished. I use it as a bit of extra motivation to get stuff painted (last time I painted an entire army for FoW that had sat in a cupboard for years). Have fun with it.