For a begginer grower, I would suggest using something very simple and that doesn't include a lot of complicated numbers on the bag. I use this mix, still am, and works great.

First, choose a soil. Just get basic "potting" soil, sterilized. I buy mine at Wal-mart(Plantsmart) for under $5 a bag. You can get any brand, stay away from Miracle Grow products altogether. You can choose any brand of potting soil though. Just make sure it is sterilized soil, and it doesn't have a lot of filler(eg. bark). Just soil.

Once you have your soil, buy a bag of Vermiculite, or Perlite. It will be right next to the soil. Again, any brand is fine. Vermiculite or Perlite just helps keep the soil lighter, so the roots can plow through and water can be easily saturated.

Once you have your bag of soil, and vermiculite/Perlite, mix 1/3 verm/per. and 2/3 soil. Mix them together.

There you go! A simple and very effective mix. I suggest keep it simple until next time, so you don't get confused... Good luck.