I'm trying to figure out where the best salt mine tour from either Munich or Salzburg would be. We will be traveling by train so we need easy access from the train station. I know there are mines in Hallstatt and Berchtesgarten (sp?) but I'm not sure which would be easier to get to from either Munich or Salzburg or if there is another salt mine that is better. Any input would be greatly appreciated.

I would say that from your city choices the easiest mine get to would be the Salzburgwerk just outside of B'gaden.
That being said, you would need to take a train or bus from Salzburg to B'gaden and then get a local bus or a taxi. There is not a taxi stand at the Salzburgwerk but I'm sure that you can make an arrangement with your driver or the folks that work at the salt mine will help you. What month is your trip?
If you are intent on seeing a salt mine your best(easiest) choice would be to take a tour(bus) that includes the salt mines from either Munich or Salzburg.This would be a good way to see the countryside as well since you won't have a car. The tourist office at the Bahnhof in Munich or Salzburg will have English speaking folks who can help you to arrange this. Depending on where you are staying, your hotel may also be able to help you out.
Bavarians are extremely helpful and your request will be met with enthusiasm in most places.

I'd personally prefer the old mining facility of Durrnberg near Hallein. Lots of history, but I don't recall how close the rail connection is. I believe it's pretty easy to get to, going just south of Salzburg. Good luck.

Thanks for your responses. Our trip will be in mid June. My kids really want to do this and I figure a salt mine is not something they will see too many other places so we should do it while it's close.

Kitty,
We did the Durrnberg/Hallein mine years ago and it was great. As I recall, it is walkable from the Hallein train station-about a mile. Very easy to do from Salzberg.

Kitty,

Do give serious consideration to the salt mine in Hallstatt, but not so much for the mine itself. While the Salz Welten mine tour is an enjoyable diversion (there are underground slides to ride and a nifty train that exits the mine), the tour places special effects (a laser show) and entertainment over information. This is too bad, given the important role the mining of salt played in and around Hallstatt.

Still, see the mine, but place more emphasis on the lovely and beautifully situated- albeit very touristy - village of Hallstatt. Also, don't miss the tour of Dachstein Ice Caves (a short drive from Hallstatt). To reach these caves, you'll need to take a cable car (offering great views of the Austrtian countryside), followed by a fairly steep walk to the cave entrance. But the effort is well worth it, as the naturally formed ice structures are impressive, fascinating. Your kids will undoubtedly give this tour a "thumbs up".
What's more, the tour is offered in both German and English. Dress warmly, however.