I'm not familiar with red wines at all....they give me an instant migraine. I am fairly knowledgable about German white wines, and I've picked up a bit about California white wines. When I was first learning about German whites, I learned about the different grape varieties, then about the different wine growing regions in Germany. Then I learned about the different harvest times for different grapes. It's actually rather fascinating. The longer a grape stays on the vine after ripening, the higher the sugar content once it's picked and used to make wine. If a ripe grape is frozen on the vine, which happens very rarely in Germany, it can be used to make a very rare, sweet (and quite expensive) dessert wine called Eiswein. Now I've figured out that my favorite wine growing region is the Mosel-Saar-Ruwer region, or the Nahe region. My favorite grapes are Riesling, Scheurebe, and Moscato or Muscat grapes. I prefer a later harvest, such as an Auslese or Spatelese. Berenauslese, Trokenberenauslese and Eiswein are far too sweet.
At any rate, if you can find a place to do wine tastings, I highly recommend it! It's fun. You can learn what types you like, what to look for when buying a wine, and how to serve it. Expensive doesn't always mean good, and I've found some absolutely excellent wines for under $8/bottle.