RTS creation guidelines?

Right, hello everyone.

So I work for this game-company (as Q.A lead, nothing fancy) and I've been tasked with (assisting in) finding out the order at which you build an RTS game.
We've never made an ACTUAL RTS game before, but since most of the office are avid RTS fanboys, we're sure to make a decent product - it's more or less a test of "me" to come up with something.

All that aside - does *anyone* one know how to start off? Basically, we have the "rules" set up (to an extent) and we have a pretty solid idea about  what has to be done.. 

Does one introduce and balance units and micro/macro economy of the game first - does one set up the map (2, 2.5 grid?)..? Basically, does anyone have any prior experience with making RTS games - does anyone know a framework for such a project..? 

Or might you lot have an idea about where one might procure some information on which order these projects are traditionally build?


Sincerely, 

me.

- "Oh. Hi. So. How are you holding up? BECAUSE I'M A POTATO!"