if your going with sc then use the terran as they are the most easy to use race. build workers untill you have one per miniral patch and then try to put up two barricks and pump out marines. as a rule of thumb for every marine you let loose to scout or whatever pop one into some bunkers to defend your base. on easy if you can create a choke point the computer will continue to mindlessly throw units at your defenses leaving you time to experment with the units before later tech trees. also tech up, if your quick and your marines have plus 1 armour when going in for the first strike for example you can crush the other two races before they start.
Also look for Primas offical stratagy guide, for a newbe that is extreamly useful
Also look for Primas offical stratagy guide, for a newbe that is extreamly useful