Your coin is normally called a Peace dollar because it was issued to mark the end of WWI and has the word PEACE on the reverse. All Peace dollars have the same mint mark position, in between the word ONE and the eagle's tail feathers. No letter = Philadelphia, D = Denver, S = San Francisco.
1934-S dollars are somewhat more valuable than the average for Peace dollars. As of 01/2009 rough retail values are:
Very worn condition - $28
Moderately worn - $50
Slightly worn - $70
Little or no wear - $200
The mint mark position on all Walking Liberty halves after 1917 is the 8:00 position. Possible letters are: Blank = Philadelphia D = Denver S = San Francisco
1892 Liberty silver dollar mint mark in on the reverse just above and between the D and O in Dollar at the bottom of the coin. Mine is marked with an S.
It's called a Morgan Dollar not a lady liberty dollar. The 1882-S is a common date/mint Morgan, circulated coins are valued at $17.00-$26.00
The 1897-S MORGAN dollar is not scarce or rare, an average retail value for the coin is $26.00-$32.00.
The 1920 Half Dollar - aka - Liberty Walking - mint mark of "D" or "S" would be located on the reverse side, just to the left and above the "H" in half dollar.
As of 09/2008 a 1925-S Peace dollar is worth $15 to $23 depending on how much wear it has.
The mint mark on a 1924 Liberty Silver Dollar is located on the reverse side of the coin, below the eagle's tail feathers. Depending on the mint where the coin was produced, it can be found as a "D" for Denver or an "S" for San Francisco. If there is no mint mark, the coin was minted in Philadelphia.
With no mint mark, around $1000 With a D or S mint mark, $1000 to $1500 depending on condition. has a g mark
W on a Walking Liberty half dollar is the designer's initial (A. A. Weinman). The mint mark location is on the back at roughly the 8:00 position - blank, D, or S.
Not being certain which half dollar you have, I can tell you that there was never an "A" or a "N" mint mark. The letters you should find will be a "D", an "S", an "O", a "P" or a "CC"
Look at the date again and post new question, the first Walking Liberty half was 1916.
On the back of the coin under the "O" in "ONE" there should either be no mark, a D or an S. If your coin has no mark, it was minted in Philadelphia. If it has a D it was made in Denver and if it has an S it was made in San Fransisco.