Believe it or not, this is simply a standard “Drop D” tuning. But after you get a drop D tuning, then every single string is tuned down an additional step. If you were to play your standard D chord in this CGCFAD tuning (across all six strings), you would be playing a C major chord.

Of course, just telling you to tune to drop D (simply tune your low E string down to D)and then tuning each and every string down an additional whole step is probably not that helpful, so you might want to try it this way:

1. make sure your guitar is tuned correctly to start with.
2. tune the A (5th) string down to G by matching the open 5th string to the third fret of the 6h string (instead of the fifth fret like you normally do).
3. once you've tuned the 5th string to G, you can then go and tune the strings above it in the normal manner (matching the 4th string to the fifth fret of the 5th string, etc). Essentially what you have done is to tune the first five strings down one whole step. Your guitar will now be tuned EGCFAD.
4. Finally tune the low E (6th) string down to C. Your can do this either by matching it an octave lower than the 4th string (now tuned to C) or by matching the twelth fret harmonic on the 6th string to the open 4th string.

Another way to tune down to CGCFAD would be to: 1) Make sure you have the guitar in tune. 2) Match the open fifth string to the fourth string while holding the fifth fret. 3) Repeat this for the fourth string. 4) Match the open third string to the second string while fretting the 6th fret. 5) Match the open second string to the first string while fretting the 5th fret. 6) Match the first string open to the second string fretted at the fifth fret. 7) Lastly, match the 6th string fretted at the 7th fret to the open 5th string. Your guitar should now be perfectly in tune. I find this method easy because its easy to remember.

C# tuning (so that when you strum the strings without fretting anything you get a C# major chord) and yes, there is such a thing. Most people think of it as Db tuning (I think because “flat” = “down” or lower in our minds) but since Db is the same note as C# it is the same tuning. Anyway you look at it, it's a step-and-a-half lower than standard tuning, meaning it would look like this:

STANDARD: E A D G B E Open C#: C# F# B E G# C#

The easiest way to get there (assuming you don't have an electronic tuner) would be to tune your 6th string down a step and a half. This would now be in tune with your open A string when you play the 8th fret of the 6th string (instead of the 5th). Once you have this string in tune you just tune it the regular way.

If you do have an electronic tuner that only works on the standard setting, then just tune the 3rd and 4th strings to their appropriate notes (B and E respectively) and then work your way to the outer strings. This will involve working “backwards” on the 5th and 6th strings, but it's not that hard.

As an alternative, you can also tune your guitar to open B and put a capo on the second fret. See the Easy Songs For Beginners lesson on God Put A Smile Upon Your Face for more discussion on this tuning.

• Guitar tuning Wikipedia entry
• Acoustic Guitar Central: Alternate Tunings