If I wanted to write a book or short story, would a speech to recognition program work? I have Windows 7 so can I just use the voice recognition software after I teach it my voice and speech patterns?
You still will have to edit what you dictated for syntax, context, grammar and spelling. No speech recognition software renders speech 100% correctly. Just look at how accurate speech recognition software is on your cable TV. If it is 75% accurate, it's doing great.
"Good enough" is subjective, and as Harry mentions, depends on accent and other factors. I would definitely try it out, try different vocal times, speeds in speech, etc., in order to find out what works and what doesn't. It will take some "training" time and learning the capabilities as you mentioned to really tell what would be best, or if it would work for you. The only other software that would offer better results is Nuance Dragon Naturally Speaking, but that normally costs around $80-100, unless you catch the deals at Newegg.com or TigerDirect.com, which can be between free after rebate to around $20-30.
The simple answer is "it depends". People can and do write books using dictation software like Dragon Dictate. The author Terry Pratchett writes using a customised dictation package since he got Alzheimers (http://www.npr.org/2013/11/03/241630751/with-fading-memory-terry-pratchett-revisits-carpet-people). The main thing that will affect any dictation app is your accent. The closer your accent is to a neutral American accent the more success you will have. As an Irish guy, dictation software doesn't work well for me at all. My accent and pronunciation is just too removed from what the people who were designing the software expected.
The best thing you can do is try it. Write a paragraph of text by hand and then record it using dictation. How closely does it match? You will always have to edit your work so a word or two that are wrong won't make a difference. If you're getting 90% sentence accuracy then I think it'll work well for you. If it's less than that, the frustrations will add up and you'll spend more time correcting than writing.