One of the voice recognition programs is called Dragon Naturally Speaking, currently owned by Nuance.
Depending on the version, a headset mic will be included, but I have used other makes and models without problems.
The software can be used for dictation, speaking the text, and navigating around menus by voice instead of a mouse.http://www.nuance.com/
Prices start at about $50 for the low end and $100 for the preferred version, there are legal and medical versions as well.
Just want to share this as I have the same problem couple of months ago and also ask help in some forums. And these all wrapped up to my conclusion.
I agree with Tanvi by using online speech to text services so you can convert audio files to text document easily and its more reliable than downloaded software.
Dragon is the most commonly used but can't be taken for professional purposes since you still have to train it.
You may also try a service like http://www.speechtotextservice.com/
or you can hire in elance, freelance, odesk, etc.
But one thing is for sure. As of the present technology in transcription, still nothing is free, unless you still do the work.
Hope this adds up FYI.