If you are one of the majority of Americans, who consume wine within 24 hours of its purchase, you are missing out on the wonderful experience of having a stock of wine that you can dip into on a moment's notice. Start the process with a mixed case from a merchant you have had some experience with, a salesperson that has helped you find wines you have liked in the past or outside advisor. Include at least 3 or 4 grape varieties or regions that you are not familiar with. Ask what kinds of food would go well with them and make a list.
Then, as you drink those wines over the next month or two, take notes. Go back and buy a few more bottles of the ones you like, as well as another mixed case, and repeat the tasting/ note taking. Repeat as often as you have room to store the wine in a cool, dark place and can keep track of what you have. Before you know it, you will have a diverse collection of wines that you like and are familiar with. The part of your brain that understands wine will grow with your familiarity with these wines, along with the ability to "taste" them just by looking at the bottle. You will start to get good at pairing wine with food and being able to find just the right thing to go with most meals, both at home and at restaurants, because you will start to know regions and grapes.
By holding back some of the ones you liked over the next year or two, and you will get a sense of how they are maturing (both for the better, or worse); tasting the same wine over a year or two, or even five is the only way to see this process "up close and personal." You should then develop an ability to size up a new wine's ageing potential after a few years of experience. I purposely will save a bottle from full cases for quite a long time just to see this type of change, sometimes surprising myself how even an inexpensive wine can be wonderful long after it should have died in the bottle.
For example, I opened up a Forrestville Merlot ($6.50 purchase price) that was in my cellar for about 7 years and it was really good. I wished I had more. Please do not be afraid to drink an older bottle, even of moderately priced wine. As long as it is stored properly (you do not need a fancy fridge), it should be fine; maybe you will like it more than you did when younger, like an old friend that grows on you.
Once you have an assortment of wine on hand that you have collected, I can assure you, it will be comforting to be able to choose something you know, without rushing out to a store on short notice.
Bernard Kenner firstname.lastname@example.org