For a collection that large, I'd talk to the local card shop and see what they suggest. Some card shops will do it themselves, but charge a fee due to the amount of time required to do it.
Another alternative is that if you've got the time, pick up a Beckett Baseball Almanac (it's an extensive price guide) and go through them yourself.
Just remember that the cards need to be in perfect shape in order to be worth full book value. Anything wrong with the card, like worn corners (not sharp anymore), off center picture, etc., takes value away from the card(s).
Oh, and if by chance any of the cards form a full set, then of course that would have some value as well. The exact value will be listed in the Beckett.
Good luck!

Yes doctor, I am sick.
Sick of those who are spineless.
Sick of those who feel self-entitled.
Sick of those who are hypocrites.
Yes doctor, an army is forming.
Yes doctor, there will be a war.
Yes doctor, there will be blood.....