Web Guitar Tutor

Learning guitar these days pretty much always involves reading tab.  If you are just starting and don't know what tab is, it's simple:  It's a 6 lines, and each line represents a guitar string.  The numbers written on the line indicates playing that fret, on that string.  The bottom line is the low E string, the top line is the high E string.  Here's an A minor bar chord:
----5----
----5----
----5----
----7----
----7----
----5----

The internet offers a huge repository of tabs, for pretty much any song you can imagine.  In my teaching, I provide tabs of whatever we are studying.

There is something to be said for traditional music notation.  It is a denser, more information-rich means of conveying musical data.  Each note can display its pitch, its duration, and its relation to the notes around it-- it is very difficult to perceive intervals from guitar tab, but it can become second nature to perceive intervals in traditional notation. 

Sght reading music is itself a discipline, and I only teach it when the student feels the need.  Of course, I encourage it.  But, tab is more expedient in terms of showing guitar riffs and licks, and you use your ear to determine the rhythmic intricacies. 

A great program to get is Guitar Pro.  It is the standard for getting tab on the computer.
 
There are many websites that offer lot's of tabs.  Here's a nice one:  G Tabs
The Guitar Pro website has a page listing many more of these tab sites.

Found a great little online trainer for locating notes on the fretboard.  Practice a little with something like this, every so often, and you will see your skill increase.  Then, send your thanks to the programmer is, and try it on your instrument.

Fretboard Warrior

If you are an iphone or ipod touch owner, then there are a few useful apps available for musical training.  I'll list a couple I use regularly:

Karajan Ear Trainer
This is far and away the most bestest, most usefullest iphone apps I have found for any purpose.  It is also one of the most pricey, at $15, but I find it to be worth the money.  It plays not only simple intervals, but also chords (triads and 7th and more), scales, single pitches and even BPM.  It has a a few different sounds, a nice layout that has an actual keyboard in landscape mode, and a report on your progress.  You can customize the program in many ways, very easily.  Highly recommended for both beginners and advanced players.
www.karajan-eartrainer.com/en/

iReadMusic
This app is a really solid tool to help learn to sight read traditional notation on the guitar neck.  It has several modes, I use  'Play that Note!'  In this mode, notes on a treble (or bass) clef are displayed on top, and the fretboard is displayed on bottom.  The frets are a bit tiny, but it's actually precise enough to go through entire scales.  The program has a lot of customization available, including other instruments (piano, bass and banjo), sounds, and types of drills.  It's only $2, so I think it's worth the investment.
www.glpsoftware.com/

Metronomes and Tuners
There are dozens of metronomes and tuners out there.  I found two for free (my usual pricepoint) that work well.
iTick
Guitar Tuner
Tuna Pitch is a $2 tuner that seems to do the job.

GigBabyFree!
How is it that my wallet-sized phone can house an entire four-track recording studio?  People over the age of 30 may understand my wonder.  In any case, here is a free recording app that has 4 tracks and some bells and whistles to boot.  Really fun, and others like this get to be more expensive.
www.iometics.net/GigBaby!/