According to the bus schedule, you can catch the bus at the Strasabourg train station or the Obernai train station.
The prices are listed on the bus schedule.
And I believe there is a shuttle in Obernai that you can take. Obernai is the largest town close to Mont Sainte Odile.
Go to the tourist office in Obernai for more information about the shuttle.
Keep in mind that Mont Sainte Odile is in the Vosges mountains so it may not be possible to go there in the winter when there is bad weather.
If you have a car, you can drive all the way to Mont Saint Odile or you can park in the village of Ottrot and walk up (if you would like to do a short hike).
Getting to Mont Sainte Odile by car is not a problem. On the main highway (autoroute) you'll find a big brown sign with a picture of Mont Saint Odile on it.
That means get off at the next exit. You'll find signs pointing the way. Go towards Ottrot if there is no sign for Mont Sainte Odile and then Mont Sainte Odile when there is a sign for it.