The following is a general startup for Earth players. If you have not decided what type of strat you would like to follow the is overall the best path to follow. When you get to the point where you have decided what government to switch to then you may switch to that government without the 14% penalty!
Step 1 - Go to your main menu, and click on country management. Set
the following options: Tax rate at 70%, production at 100% TURRETS.
Don't change your government, stay Monarchy. Then click on purchase,
then on sell military. Sell your 100 troops.

Step 2 - Build 1CS (see list of stands for)

Step 3 - Go back to country management and set tax rate to 35%. It will
stay at 35% for the rest of the game.

Step 4 - Build 39 more CS. You might need to build 10 or less at a time
since you are low on cash, but be sure to build exactly 39 more CS.
You are done with building CS for a couple of turns now as you have 40 of
them now.

Step 5 - Build 15 industries. As you see, from now, you are producing
turrets. Every single turn from now on, you will click on purchase, then on
sell military and sell all your turrets (this is to reduce every turn
expenses). If I tell you to build 60 industries, it means build 15 industries,
sell spies, and repeat this 3
more times.

Step 6 - Build 45 industries. Remember to sell turrets every turn!

Step 7 - From now on you will do the following until turn #75 (you can see
how many turns you played by clicking on status). So do this:
Explore one turn. Sell turrets. Click on build, check if you have enough
money to build 15 industries. If so, build them, then repeat the operation.
If you don't have enough money to build 15 industries, then explore once
more, then sell turrets and build the industries (or repeat
this operation until you have money for 15 industries).

NOTE - To make sure that you don't run out of food, when you start
running low build 10 farms and 5 oil rigs, instead of 15 industries, but only
one time. Be sure to spend one turn doing this even if you don't run low
on food, just to make sure that you'll have the oil rigs when out of
protection.

Step 8 - I hope that you stopped doing #7 at turn 75. Right now you
should have around 250 industries, maybe more... Some free land, and
40 CS. Sell the rest of your spies.

Step 9 - Go to your main menu, then country management, and switch
production to 100% jets (or turrets depending you want to be offensive or
defensive when you are out of the first 100 turns protection).

Step 10 - Similar to step 7. See if you have enough money to build 15
industries. If not, explore once. However, if you still don't have enough
money, build 4 CS. Repeat this step until that you have 20,000 jets or
more (check your status every couple of turns. You must stop doing
this step as soon as you get your 20k jets.)

Step 11 - If it's not turn 100 yet, build CS until it is. Then click on market,

then sell goods. Sell 5000 jets (25% of 20000).
Earth's General Startup Strategy