How do you determine on a silver dollar if it is minted and where would the o or s be located on the coin I have a 1846 silver dollar but cannot find its value due to not knowing what to look?

The mintmark on a Seated Liberty Dollar would be located on the back of the coin, beneath the eagle's talons. It could be "S" (for San Francisco), "O" (for New Orleans), "CC" (for Carson City), or there could be no mintmark, signifying that the coin was minted in Philadelphia.

1846 dollars were only minted in Philadelphia and New Orleans. The San Francisco and Carson City mints weren't established yet.

As of 03/2009 Numismedia lists retail prices for an 1846 Philadelphia dollar ranging from $215 for a very worn coin to over $2000 for an uncirculated specimen. If it has an O mint mark the range is $270 to $6000+

In any case you should have your coin professionally appraised.