Force hosts a series of very clear and concise instructional videos via his You tube channel: Starcraft 2 Strategy.
His videos include descriptions of build orders, specific openings and general in-game strategy. They are an excellent resource for learning tight openings and for building a general knowledge of the strategies available to players.
You can also check out his website at: www.forcestrategygaming.com
Recommended
Starcraft 2 – [Z] Macro Play, Upgrades, When to Drone – Highly Recommended
In this video Force discusses a longer-term game plan with a focus on Macro. He advises on when best to get upgrades and when to build Drones. This game is an excellent example how much more units you can have if you can expand more than your opponent. Force also provides some helpful advice on when to pull Drones to assist in defence.