There isn't really set guide, but maybe these couple of things can help you out some.

Not sure if you've been to the wiki yet, but it has a lot of good info. Abeit some of it is a littel outdated, but still usefull nonetheless.

Also since the search is useless here a good thing to do is use forums.galciv2.com as the critieria to search with your favorite search engine. Search for strategies should return a whole lot of good info.

And as always if you get stuck on any certain thing fell free to ask. There is a lot of good knowledgable people around the forums.