I have a few tips on how to succesfully use and draw with colored pencils. 

1. Buy Prismacolor or Faber-castell Polychromos: They may be expensive, but if you take art seriously, you'll be willing to spend the money on them. I suggest Prismacolor personally, I bought a cheap 132 pencil set online for less than $100.
2. Buy blenders: not those blending stumps you get at michaels for graphite pencils. Buy either a Prismacolor colorless-blender pencil. They are $2 each, and very helpful, those they do dilute the color a bit and leave a grainy look. You can also buy a bottle of Mona Lisa Oderless Paint Thinner, just a SMALL amount on a brush or cotton swab can help colors blend well into eachother. Make sure you open a window before using it however, it can give you quite the headache. 
3. Test: Before you actually start coloring, test out the colors on a scrap paper and mox them while looking at your reference, try to get the closest color posible before you put it on paper.
4. Remember: Colored pencil is hard to erase. I suggest an small electric eraser to pick up as much color as you can, but it wont correct all your mistakes, some color will be left behind. So draw carefully!
5. LAYERS: For the love god, ad layers. If an apple was just red, we would only need one pencil. Color lightly first, so you still have those white spots in the color, and build on that, at more and more color before you press it into the tooth of the paper.
6. Burnish: It's similar to layering, but you start to press harder and harder with your pencil, pushing the color into the tooth of the paper, giving it that glossy texture. It's also similar to blending, because when you are pushing down and coloring fast, the wax color heats up and melts into other colors.
7. Coloring: When coloring a large area with a single color(like black) try to avoid scribbling in straight lines, or you will see the direction you moved in. Try coloring in small cirle motions instead.
8. Base color: When coloring something like skin, which has many tones and reflects light easily, always find a base tone to use. With a base tone you can then add other colors on top of it and you'll see the underlying color peeking through, like in natural skin.
9. Do not: Do not leave those white specks of the paper show, push hard with your pencil.
10. ALWAYS: draw out your picture in pencil first, and note the significat hue changes.
11. Buy: A white paint marker, for those spots that just wont take white pencil anymore. It's helpful for the light reflections found in eyes and in metal.
12. Cheat: If you have a large background area that needs to be colored, cheat and use paint to fill it in, it will look neater and take less time.
13. Have fun!: Be opptimistic about your work. If you mess up or it looks kinda poff, start a new one! You can only learn by making mistakes.