My personal recommendation is coco. Botanicare coco in the bag + General Hydroponics Micro at 6ml/Gallon + General Hydroponics Bloom at 9ml/gallon. Use water from a reverse osmosis unit ($80) and mix in a 5gallon bucket at a time. If you do exactly that formula and water every day when the lights come on, watering just enough to start to see runoff, you pretty much can't screw it up. Buy a good pH pen to ensure you pH is between 5.7 and 6.0, this is the ideal range for coco. I use this pen and it's all I'll ever need:
http://www.amazon.com/Hanna-Instrum...60&sr=8-1&keywords=hanna+instruments+hi+98129
To germinate seeds, I fill a red solo cup with the coco, leaving 1" of empty space. I water through thoroughly with pure water from my RO unit to ensure the coco is properly moistened, stirring it around with my finger to break up chunks and air pockets that stay dry. I place the seed on top of the coco once it's neatly smoothed flat, lightly powder with a mycorrhizae root innoculant, then add a light covering of dry coco over the seed, about 1/4". I do not water at this point. I take a clear plastic bag and make a little tent over the cup and seal it shut with a rubber band. I put this under a compact florescent light and walk away for 4 days. On day 4, I check progress and maybe add a few drops of RO water. Once I see the seed pop up above ground, I remove the plastic bag and move her under the light I use for vegetation/seedlings.
When the seedlings are small, dilute the nutrient solution to 1/4 strength, check to make sure pH is 5.7-6.0 (use a pH adjustment product if not stable), then water very very sparingly, just around the outside of the pot. I water when the pot seems very light, but am careful to never let a seedling go dry more than the top 1/2" of their container. If you stick your finger in and it's dry below 1/2" you are under watering. Coco is perfect for beginners because so long as your pH is correct, you really cannot over water the medium except in the first few weeks of seeling life. By week 3, it's a daily watering, week 6 through finish you can pretty much water 4-6 times a day, especially if you're growing autoflowers under 24 hours of light per day!