Miracle grow is frowned on by a lot of people on the boards... I mistrust it too, perhaps irrationally, but some posters have great results with the stuff.
Just be careful because small sprouts can't take much fertilizer and the pre-ferted soils might burn them.
If you can find the organic miracle grow soil buy that instead. If you're starting out with something that is already supposed to be a complete potting mix, 1 bag of perlite should be mixed with 2 bags of potting mix.