Jul 2nd 2014, 2:29:52
Here's the few quick tips I'd suggest to anyone, some of them have already been said here:
1) Find some good mentors who can work with you one on one. The easiest way to do this is to join an alliance.
2) Specialize with your country. That means you'll want to focus on either making food, making tech, making military, or just cashing in on tax dollars, then sell whatever you make to get the other things.
3) Don't use any attacks other than Standard or Planned Strikes, and don't use any spy ops other than Spy and Military Spy. People tend to see the other spy ops and attacks as acts of war and they'll retaliate harshly.
4) Watch the forums and read the wiki. If you decide to go solo, you need to learn the politics of the game at least on a basic level. The game itself is just a bunch of game mechanics, but the players have established policies over the last 15+ years that flesh out the game quite a bit. If you don't learn these policies and understand how to interact with others, you'll become a punching bag.
That's a good start, but ultimately as Dragon said, join an alliance. It's the easiest way to learn to get veteran players helping you along with all of the above.