The suggestion above of putting C at 12 o'clock, and C# at 1 o'clock, etc., misses the point something grand. C should be flanked by the 5th (clockwise) and 4th (anticlockwise) -- G at 1 o'clock, and F at 11. Then from the G, go 5 to D (2 o'clock), then A (3 o'clock), etc. If you follow it around to 6, you get B. Then use the anticlockwise count by 4ths from C to F (11 o'clock) to Bb (10 o'clock), Eb (9), Ab (8), and Db (7).

The result is a chart that gives you the I, IV, and V chords in three adjacent locations, and the relative minor for any chord is always 4 numbers clockwise from the starting position. To do jazzy "circle of fifths" numbers, start anywhere, go clockwise three* or four** numbers, and move back (widdershins) in one-number increments to the starting position.

And, as it happens, if you start with C at zero, the number of each note is the number of sharps (clockwise) or flats (anti...) in the key. So G is 1 in the sharp direction, and F is one in the flats. G has one sharp, and F one flat. D is two sharps, Eb is three flats, etc.

So it's a circle (clockface) of 5ths (going clockwise).

Bob

* Don't Let Your Deal Go Down, for example
** Five Foot Two, for example