Traditionaly you will find Wienerschnitzel served with pomme Fritz,
An Austrian style potato salad, made with just broth and onions no bacon.
You will also see it with boiled potatoes tossed with butter and parsley.
Also you could serve it with ligonberries, while this is not traditional it is very tasty,
Another side dish that goes well with this is Cucumber Salad.
I like to serve Rohtkohl with it but this is not traditional.