C&C:ZH - Ideas on the most efficient build strategy

Hi All,

I haven't kept up with C&C, but want to start play again, however,
I'm looking for steps/tips on:

1) A strong opening build sequence for USA, China, and GLA. 
2) Which combination of units you find most effective.
3) Any home base defensive tips

Any constructive feedback is much appreciated.

Thanks,
B