Start with basic strength training. Most workouts for your major body parts should start with basic, multi-joint strength training exercises that allow you to lift more weight overall, such as the bench presses for chest, overhead presses for deltoids, barbell rows for back and squats for legs. This will allow you to lift heavier on these exercises, while you're still fresh and have enough energy to better stimulate muscle growth.
Go all in. Doing high-intensity workouts is the key to building muscle. Light workouts, even if they're long, don't go nearly as far to produce the right conditions for your muscles to break down and rebuild. Plan on doing a 1-hour session 3 - 4 times per week. This may sound like a surprisingly manageable plan, but remember that during each session you have to make it as intense as possible. Don't worry, your muscles will definitely get sore - and you'll soon start seeing some definition.
During each session, lift as much weight as you can using the correct form. Experiment to find out how much weight you should lift by doing reps with different weights. You should be able to do about 6- 10 reps without having to put the weights down. If you can't do more than 2 without feeling like you're going to pass out, go lower.
If you can do 10 or more reps without feeling a burn, add more weight. You simply will not get bigger unless you challenge yourself to go all in.
Lift explosively. Do each exercise quickly, rather than slowly, for maximum muscle gain. Another way to put it is to "lift explosively"; instead of worrying about reps, time each exercise and lift as many times as you can. until the time is up. 
Use proper form. To develop precise technique, do every rep with good form. Beginners, strive to keep the rep target inside your strength capabilities. Find the right groove for each exercise. Don't train to failure when you're just starting out.
You should be able to complete the full motion of an exercise without having to lean over or change position. If you can't, you need to be lifting less weight.
In most cases you'll start with your arms or legs extended.
Work with a trainer for a few sessions so you'll learn the right form for different exercises before continuing on your own.
Alternate muscle groups. You don't want to work out the same groups with every workout, or you'll end up damaging your muscles. Rotate muscle groups so that each time you work out, you're putting in an intense hour working on a different group. If you work out three times a week, try something like this:
First workout: do exercises for your chest, triceps and biceps.
Avoid plateaus. If you do the same thing over and over each time you work out, you're not going to make progress. You need to be adding weight, and when you plateau with the new weight, switching up your exercises. Stay aware of the progress you're making and take notice when it seems like your muscles haven't changed in awhile; it could be a sign that you need to switch things up in the weight room.
Rest between workouts. For someone with a fast metabolism, the rest period is almost as important as the workouts. Your body needs time to build muscle without burning a lot of calories doing other activities. Running and other cardio exercises can actually impede the growth of muscles. Take it easy in between workouts instead. Get a good night's sleep so you're fresh for the next workout.
Develop the mind-muscle connection. Research confirms that tuning in to the mind-muscle connection can optimize your results in the gym. Instead of focusing on your day, or the blonde next to you, strive to get into a muscle-building mindset to help increase gains. Here's how to do it:
Visualize your target muscle growing as you complete every rep.
If you're doing lifts with one hand, place your other hand on the muscle you're hoping to improve. Doing this can help you feel exactly where the muscle is straining, and help you refocus your efforts.
Remember, it's not the amount of weight on the bar that's important; it's the effect of that weight on the muscle that leads to increases in the size and power you're after. This has a lot to do with how your thinking and what you’re focused on.