Student Guitars and Accessories

The advice presented here is intended for those who seek to get started playing guitar while keeping the initial expense to a minimum.
For those who desire to buy a high-end instrument and aren't concerned about the cost then, by all means, do so.
Not all guitars are the same.
If you are looking to purchase a first guitar (for yourself or a child) and begin taking lessons I strongly recommend a nylon string 'Classic' guitar as opposed to a steel string 'Folk' guitar.  It will be easier on the fingertips and can be played either fingerstyle or with a pick.  Also note that, if purchasing for a child, guitars can be offered in 3/4 and 1/2 sizes - It is important to get the right size.
Not all guitars are created equal.
I have yet to find a satisfactory guitar in any of the mega-discount stores (Walmart, Best Buy, etc.)  Buy everything else in those stores, just not a guitar.  I recommend purchasing from a local music store (where you should receive good advice and have any questions answered [if not - leave!]) or ordering online if you know what you want.  Some inexpensive student guitars that I have worked with and consider to be of good value are those by Cordoba and Yamaha.  There are many others that are just as good but I can only recommend what I know.  If ordering online read the reviews.  If a lot of people are happy with a product then you probably will be too.
Cordoba Guitars at Amazon:
Full size student model: <Cordoba C3M>
Another popular model: <Cordoba C5>
3/4 size student model:  <3/4 Cordoba>
Yamaha Guitars at Amazon:
Full size classical model:    <Yamaha C40>
1/2, 3/4 & full size models:  <Yamaha CGS>
Method Books
The books listed here are for the classical guitar student only.  Non-classical students need not purchase any of these.  A determination will be made after our first meeting which, if any, book should be purchased.
Beginning Classical Guitar Method Book: <Classical Guitar Method>
This is the book I use with all my beginning classical guitar students.  It is excellent!  After having reviewed many of the other popular classical guitar method books available I find that this one is the best introduction to classical guitar and it progresses the student quickly. 
Intermediate Repertoire Book: <Repertoire Book>
I frequently work from this book with my intermediate level classical guitar students.  It contains 75 pieces in a graded arrangement and includes a CD recording of all pieces.  Definitely worth adding to your library.

'Miniatures' Book: <Miniatures Book>
Liona Boyd's 'Miniatures for Guitar' is an excellent collection of beautiful, yet playable, classical guitar pieces.  This book/CD combination is definitely another 'must have' item for the classical guitar student.
Electronic Tuners
A good electronic tuner is an important accessory that will keep you playing in tune and won't cost you much.  I own a Korg tuner that stays on my music stand all the time.  It cost less than $20, is durable, accurate and the batteries (2 'AAA') seem to last forever.  Highly recommended.
Korg tuner at Amazon: <Korg Tuner>
Foot Stools
A foot stool is a required accessory for the classical guitarist.  Recommend for other guitarists who play while seated.  You can find basic metal foot stools with rubber padded tops and fancier wooden models.  It really doesn't matter.  I have a wooden one.  Here are a couple of examples:
Guitar foot stool at Amazon: <Foot Stool>
Music Stands
A music stand is an inexpensive and very handy accessory.  Might as well include one if you are already ordering any of the items above. Doesn't need to be this exact model.  Anything similar will do just fine.
Music Stand at Amazon: <Music Stand>