you will not find it all in one place and some of the information is just flat wrong but as a start...

go to announcements and see the "repost of new Lg rules" thread
go to announcements and see "new gov type dictatorship" thread

as you have no doubt noticed the reports you receive are wildly inaccurate things like you lost 146 acres and 3000 buildings(stolen)

the admins are aware of these problems and about four months ago they were working on a fix
we are still waiting

the wiki says that GDI affects LG returns
not sure if that is true

finally you need to understand ghost acres so that you will know your return from hits on tiny countries
so read everything on ghost acres
too numerous to mention here but do a search under options for qz's statements on ghost acres
the admins encourage hitting small guys with ghost acres

finally you need to understand the admins hate it when you hit a country that grew faster than you did

so there is a huge penalty against hitting higher NW countries
i am not sure why the admins put such a premium on fast growth but do not bother hitting low-defense countries which are bigger than you because the returns are insanely small
instead triple tap a tiny country
you will get a lot more land

hope this helps