Hey Mert,
I'm an oenophile, so I'm totally jealous, but happy to live vicariously.
While I'm a red lover, I do have a few favorite producers who do a wonderful white-- The best IMHO is Cakebread..everything by them is freakin' amazing; not cheap, but so worth it. Even my Corona, Stella Artois on special occasion drinking husband said Yum to Cakebread.
What I do:
I give the sommelier three producers to use as a yardstick; one high, medium, lower price to give an idea of your taste. For example, tell the sommelier you like Cakebread, Stags Leaps, and perhaps Rutherford, then ask him/her to suggest wines, and make sure you ask if they have a captain's list and/or 2nd label list. You may find an excellent wine at an excellent value.
Also, if you're not a wine drinker but need vino to do the shop, think Prosecco (sparking Italian wine) or my new favorite Sparking Italian Red -- Wow, is that good stuff.
My best suggestion, is not to get hung up on the grape, which can be tongue twisting and hard to remember, and to use the sommelier. It's his job to find a wine that you'll like and that's within your price range.
Lastly, I have a subscription to various wine magazines, which have online tools. If you're that concerned, I'll give you the code, and you can see what Wine Spectator and Wine Enthusiast has to say about the available wines-- go online and view menu, then wine list.
PM me if you need me, and PM me after the shop !!
Have fun !!