The baritone clef determines the position of the F note on the staff 
From this reference, all others music notes will be placed before and after the F note:
Below are more music notes in baritone clef and some music notes with ledger lines:
When is the baritone clef used?
Nowadays, the baritone clef is only used for transposition, it is used by orchestra conductors and by some players who need to transpose.
This clef was used in the past for keyboard music, like for the harpsichord, here is an example of a manuscript from the Bauyn manuscript with the work Courante for harpsichord by François Couperin (1668 - 1733) (source).
Examples of the use of the baritone clef
Baritone clef for orchestra conductors
Orchestra conductors must read music notes in baritone key to transpose some scores in real pitch. Here is an example of an alto flute in G. If the conductor wants to read the score of the alto flute in concert pitch (in C), he must read the score with a baritone clef to transpose at sight:
Baritone clef for horn players
Nowadays, french horn instruments are in F, but sometimes they must use the baritone clef to read score that was written in C (written for the natural horn).
Here is an example with horn score in C from the Great Mass in C minor by Mozart:
Modern horn players must read this score with a baritone clef to transpose from C to F, what a hard work!
How to draw a baritone clef
Draw a dot on the third line.
Draw a curve clockwise.
Draw two dots around the third line.
Key signatures in baritone clef
Here are positions of flats and sharps in the key signature on the staff with a baritone clef:
Evolution of the F-clef symbol
In the book A history of music by Charles Villiers Stanford and Cecil Forsyth, a representation of the evolution of the F-clef symbol is exposed (source):
Learn to read baritone clef
Here is a game to learn baritone clef notes: