This sounds like a pretty hairy question, but I will try to answer
this in a limited fashion for beginners. What you're basically looking
for is some simple-minded strategy that will get you through the first
20-30 updates while you're still learning the ropes of the game. Try
to follow these two basic principles: Produce and colonize. Your first
and foremost need is to produce resources on your home planet so that
you can start building ships. The fastest way to start producing is to
spread out and cover your home planet as quickly as possible. This
will be the sum total of your turns for the first several updates.

Once you have resources, you get to start building ships. If you're a
metamorphic race, that means you get to build pods. This is something
you should do as soon as you get resources. This is one of the major
advantages to playing a morph...pod-building ability. The nice thing
about pods is that you don't need factories to build them, which means
they can be built on the ground and launched immediately. Since pods
are slow relative to most ships, however, it is imperative that you
launch them quickly so that you have a fighting chance to win the race
to all of the unoccupied systems.

If you're a normal race, you should build a factory as soon as
possible and then modify it so that it can start producing cheap
shuttles. After you've played a game, you'll realize why it is so
important to win the race toward unoccupied planets: it is far, far
easier to take an unoccupied planet than to kick a hostile race off of
that planet.

The best advice I've heard yet is that you should be sure to
understand the commands in the game so you can use them to your full
advantage! It takes time and experience to learn the game, and it will
be a rewarding and fun experience if you approach it in the right way.