Multiplayer tactics
 
  OK. We all know that multiplayer is the most important part of this game and nobody wants t be humiliated in the battle on the Internet. I won't claim that I'm the master of the game but I can say that I'm pretty good. I win more than I lose. Here is my advice.  
  First I'll show you how to start building in Tiberian Sun in 10 pictures. I find this building order quite effective:  
 
This is the beggining. You have 10 units and the Mobile Construction Vehicle (MCV). Find the nearest tiberum field and deploy the MCV.
MCV, when deployed becomes the construction yard which is used to build all the other buildings. First build one power plant. That should give you enough power for the beggining.
Then build two refineries. Sometimes when playing against NOD it's better to build barracks and then two refineries. That is the choice I leave up to you.
Then build your second power plant and barracks. Quickly start producing light infantry and disc throwers which you can use for scouting and basic base defence.
Then build war factory. I use the factory to build two harvesters first and then start producing units. Ussualy I start with a coupple of hover MLRS and a few titans. When playing against NOD it's advisable to build Mobile Sensor Array which will detect cloaked and underground units.
Then build radar which will give you access to mini tactical map in the upper right corner of your screen. By now you should have revealed large portion of the map. Use tactical map to scout unrevealed regions.
Build one more power plant and then build GDI tech centre. That will give you access to more advanced buildings.
Then build a few power turbines to increase your energy supply and build GDI upgrade centre. All this time you should also build vehicles and infantry units to protect your base against attacks.
Build Ion Cannon uplink and place it on the upgrade centre. Then rest from building new buildings and concentrate on building units and placing them arround and in the base for best possible defence. Depending on your opponent tactics you can build pavement arround your important buildings to prevent sneak attacks by underground units.
Then depending on map type and your opponents tactics build suitable units. Then you can build helicopter pad which will enable you to build air units. I find carryall especially usefull for transporting APC's and mamoth tanks near or in your opponents base.
  The rest is up to you.