Mods to use!

[Wrana]

Second Gandalf's opinion. Actually, I wouldn't even try to "research nations, strategies, etc." before playing. It's much more interesting to discover them by yourself. Of course, if you want to start playing MP right away, then you should know your nation and strategy before start - just to not be a boring opponent! Otherwise, it's better just to plunge in and see what interesting bits you'll discover. And another thing - many strategies you'll find here are min-maxed from a point of view of a particular player with his personal style of play. And sometimes they also require a particular patch or mod version to use verbatim, while before getting some personal experience you just don't see which things of them are more generally applicable.
The only thing I'd say is essential is "Lies my rulebook told me" thread. This you should study right after the above-said rulebook.