there is not really a solid standard unless you are following a particular ideology of tech diving etc... such as the GUE referenced earlier. they also use the same or near same configuration as most DIR divers as the picture posted already.
First you will only need two first stages. and at least one second stage on each first or it kinda defeats the purpose. Most people do not then use a third second stage for a safe second to be passed to a buddy. they just donate one of the two seconds they have that they are not using.
you really only need one gauge set or computer if you chose to use an air-integrated computer. if there is a problem you will quit the dive so one gauge is usually enough. it is a good idea to make sure that gauge or air integrated computer is on the opposite first stage to the one you intend to start off breathing from. this way you can catch early if your isolator valve is inadvertently closed etc...
Of course this all assumes that you are diving manifolded doubles. some people at times dive a separated doubles, I have done this before. in this case you have the same concerns except that you will need at least two gauges, one on each reg. and don't forget to switch from one tank to the other every so often to avoid off balancing your self.
I personally have a wireless computer (vytech) so I put the wireless module on one reg and a basic dial gauge on the other reg. but I don't dive doubles often as I don't personally own a set. I barrow them. so there you have it. But then again I am kind of conservative as I dive with a basic gauge on my single recreational regulator even though I have the wireless.
There are a lot of ways to setup a double set. some others have given a few references to how it can be done. most are minimalists. seeking some training or intro is not a bad idea if it is available to you or at least looking at some of the websites. the one thing I would say is that real quick you end up with a lot of hoses going all over the place and I personally like to minimize the confusion of a setup while still providing what I think that I need.
but these are just my ideas, and the ones above are the ones of those whom have provided them. as well as any other source you can find. Take what you can from everyone else but temper it with your own comfort, requirements, and style.