left-handed guitar (thing)

Well, I'm not left handed either. This is intended to explain why some people would want to choose a left handed guitar over a righty, or vice versa. Personally, I used these ideas when teaching friends to play guitar.

WHAT ARE MY OPTIONS?

Discussed in order, we have:

1. Buy a righty guitar, play it right handed.
2. Buy a righty guitar, play it left handed (that is, upside down)
3. Buy a righty guitar, restring it, play it right handed.
4. Buy a righty guitar, restring it, play it left handed.
5. Buy a lefty guitar, play it left handed.
6. Buy a lefty guitar, play it right handed (upside down again)
7. Buy a lefty guitar, restring it, play it lefty.
8. Buy a lefty guitar, restring it, and play it right-handed.
9. Give up and buy a piano.

Because it depends on what you're looking for.

Guitar playing tends to favor the fretting hand, which is usually the left in a right handed guitarist. (Bass playing is usually more in the right hand; adjust accordingly). A southpaw may find s/he has an advantage when starting out to have their dominant hand be the one in control. Or, you may be going for looks, or completely unsure. That's why I wrote this.

WHAT'S THE DIFFERENCE BETWEEN RIGHTY AND LEFTY GUITARS?

Shape, mostly. The guitars were (usually) designed with the comfort of the musician in mind. To determine the polarity of a guitar, hold it upright, with the strings facing you, and:

• Check the cutaways (the part of the guitar, near the neck, which 'dents' the otherwise hourglass-shaped body). In a Les Paul or Telecaster style guitar, the cutaway is on the right side of the neck (viewed from the front). On a Stratocaster style, the longer 'arm' is to the left of the neck. If you're looking at a SG-style guitar, or most acoustic guitars, you may want to keep reading.
• Look at the knobs on the body. They are usually placed so as not to interfere with the strumming. Therefore, on a right handed guitar with the head at 12 o'clock, the knobs should be between 4 and 5 o'clock.
• Observe yon strings. A right handed guitar will have the thickest string furthest to the left.
• Dig that crazy pickguard (the deformed-teardrop piece of plastic next to the soundhole on acoustic guitars and the strings on some electrics). It should be to the right of the strings on a righty guitar.
• Check them tuning pegs. This isn't always the best method, since some manufacturers like to put them on upside down for whatever reason. But usually, the majority of the tuning pegs will be on the left hand side of the head.

1. Righty guitar played righty.

This is the default. Nearly all righties choose this because it's easier and cheaper. Some lefties go this way in order to be able to play their friends' guitars, or to enjoy the aforementioned dominant hand advantage.
Right handed guitars are the norm. Often, you'll have to pay more for a lefty guitar, since they are nonstandard and aren't (mass) produced in the same quantity. Some lefties go this route to defray the costs.

2. Righty guitar played lefty.

A lot of lefties choose this method; they get the comfort of playing in a more 'natural' way with the lower cost of a righty guitar, and the ability to play most of their friends' guitars. Plus, Hendrix was famous for this.
Unfortunately, this isn't that comfortable. The knobs, as mentioned above, are in a rather uncomfortable place for strumming, and you may turn them accidentally while playing. The strap buttons are usually in inconvenient places, resulting in the strap being too short or otherwise in the way. (You can, of course, drill a new hole to place the strap button in, if the cutaway isn't too sharp). And if the guitar has a tremolo bar, said bar will always be in the way, not to mention nearly impossible to use due to its location.
Some concepts may come easier to you this way. Tablature is written upside down, and the high string is often referred to as the 'top' string. To you, it actually will be.

3. Righty guitar, restrung, played righty.

There's no real reason to do this, unless you somehow learned on an upside down lefty guitar (q.v.) and want to have a righty guitar to freak the normals or whatever reason. But it is an option.

4. Righty guitar, restrung, played lefty.

A lot of lefties who get righty guitars go this way (including our friends Jimi and Kurt). The biggest problem here (aside from those already mentioned in option 2) is that of the nut.
The nut is that little (usually) white thingy at the top of the fingerboard that holds the strings in place. The nut is usually cut to accommodate the various string widths. If so, you're going to have to remove it and turn it around; otherwise the improper cut will slowly buzzsaw away at your strings and slice them in two. It's probably best to let a trained professional handle this; however, said professional may simply try to sell you a lefty guitar, or charge you so much that you might as well buy that damn lefty guitar.

5. Lefty guitar, played lefty.

The easiest (if more expensive) method for lefties (and righties who want that whole dominant hand advantage thing). The guitar is actually molded to fit your body shape, the knobs and dials and various twisty things are all in the right places, and the strings are set up to mirror a righty guitar.
It may be easier to have a right-handed teacher when using one of these, since you can simply mirror exactly what s/he shows you.

6. Lefty guitar, played righty.

See the disadvantages in option 2. Plus, it's more expensive. But hey, it looks cool.

7. Lefty guitar, strung righty, played lefty.

Lefties who learned on an upside down righty guitar usually choose this option after getting a little more serious and a little more money. If you didn't start that way, this is probably not the best idea. But it works for Dick Dale.

8. Lefty guitar, strung righty, played righty.

I can't see a good reason besides "looks" to do this. Thank you, drive through.

WHAT ELSE DO I LOOK FOR IN A GUITAR?

Better people than me have already handled this. Please see the excellent writeups under How to buy an electric guitar.

HOW DO I LEARN TO PLAY THE DAMN THING NOW THAT I HAVE IT?

That, too, is beyond the scope of this writeup. See how to play guitar, buy a couple of chord books and stuff from the same place you purchased the guitar, or look at ads in the store, newspaper, or bulletin boards. It's hard to make a living playing the guitar, so some people try to make one teaching it instead.

IS THAT IT?

Pretty much, for now.