As posts above me have mentioned, my advice would be get an 'entry level' guitar first.
As commited as you may be to learning now, the fact is it will take time, and it can be frustrating. You don't want to spend $1,000+ on a nice guitar only to realise you don't enjoy it/it is too frustrating/you get bored of it, or whatever.
Try stuff like Squire (Fender's sub brand), Epiphone (Gibson's sub brand- check out their Les Paul range), or some LTD's (ESP's sub brand. They offer things like V's etc.). Ibenez also have some entry level models.
My first guitar was an unknown brand Telecaster. It was pretty cheap, but man, it has a good sound and character- I still use it alot! Shop around, and don't be scared by unknown brands, because you can find some real gems.
Generally, if you're just starting leaning, I'd recomend the basic shapes- your Strats, your Telecasters, your Les Pauls, as you will spend alot of time sitting and practicing and these shapes are more comfortable when you sit, and are more balanced when you stand.
Too many times I see mates who's parents buy them an awesome guitar ($1000+) as their first guitar, only for them to get bored a few weeks later, and this awesome guitar becomes just a dust collector. It's a shame, and is a bit annoying to hear about.
And at the end of the day, you spend $200, $300, or whatever on an entry level guitar. If you give up, you save a bunch of money. If you're dedicated and are going well and are enjoying it, you can look at more higher end models. By that time you should be good enough to play stuff and start writting, and you're only a few hundred bucks down, and are sure that a more pricey purchace will be worth it.
Plus it's good fun working up the 'levels' as you improve!