More good info:
The key ingredient in a Vienna-style lager is Vienna malt. This should make up the majority — if not the entirety — of your grain bill. Vienna malt is a 2-row base malt that is darker than most pale malts, but lighter than Munich malt. Pilsner malts, and generic 2-row pale malts, usually fall around 1.5–2 degrees Lovibond (°L). English pale ale malts usually rate around 3 °L. Vienna malt is typically rated around 3–6 °L, while light Munich malts rate from 8–12 °L and dark Munich falls around 20 °L. Homebrewers tend to think of Vienna as a extra-light version of Munich malt.
A beer made from all Vienna malt has a malty character, with a slight biscuity or nutty aspect, but that description really doesn’t do it justice. Just as Munich malt has a distinctive character that you can recognize once you’ve brewed with it, so does Vienna. Vienna and Munich have a similar malty/grainy flavor, but you can tell them apart without much trouble if you’ve brewed with them a couple times. Weyermann, Durst and Briess make Vienna malts that are available to homebrewers. Weyermann also makes a Vienna malt extract, called Vienna Red, that is made with Vienna malt, Pilsner malt and melanoidin malt.
When formulating your Vienna recipe, keep it simple. Although I have outlined a few options to accent the Vienna malt, all are optional. And personally, I don’t think Vienna lagers benefit from adding a bit of this and pinch of that for complexity — start with a base of Vienna malt and maybe add one or at most two other grains to tweak the flavor.