Getting off to a good start is vital to winning a game. Begin By assigning all four of your scvs to a separate mineral field. Use the 50 minerals given to you at the start of the game to build an additional SCV. When the SCV is completed, assign it to a seperate mineral field. Build a 6th, 7th and 8th SCV. While the 8th SCV is building, use the 7th to construct a supply depot. Since the Terran Race take up a lot of room, I recommend building them alongside the edge of the map top save space. Continue building SCVs while the depot is building. Once you have an excess of 400 Minerals, build an expansion command center near some more minerals. Continue building SCVs and Supply Depots when necessary while the Command Center is being built. From this point on you want to continue constructing SCV's and supply depots along with marines. Also keep teching so that you can build stronger units that can do more damage. You also need to make sure that you keep upgrading your units so they are more effective.
Terran - Base Defense and Nuking
Terran is probably the race with the best ability to defend its base from opponents. The first way is has this are its fast firing missle turrets which shoot more often than spore colonies and photon cannons of the zerg and protoss respectively. They also have the ability to make the long ranged and powerful siege tanks. Enough of these tanks close together will thwart any ground attack thrown at them. This makes them a very powerful asset. Once your base is made impenatrable you should be able to focus solely on the production of ghosts and nuclear missles. These are most definately the most powerful 2 things in the game when combined correctly. The ghost can be cloaked and in many cases wont be found until its too late. This makes it a very powerful unit and strategy
