Which area are you headed to?
If youre going to kelowna, you might as well check out Mission Hill and Quailsgate. They are commercial wineries. Mission Hill has a nice view.
If you venture further out then you can find more boutique wineries, esp in naramata where they have a section called the "naramata bench" where there are about 22 wineries on a relatively short stretch of road. I'd recommend this because you can be more productive this way. If you do go here, check out La Frenz (prolly the best, they dont need to sell in stores because people come to them and buy them out), Township 7, Elephant Island (fruit wine, sweeter stuff), and Lakebreeze.
Wine tasting is prolly easiest with a group of 4. Just go into the shop and stand at the counter and theyll get you started. If you are planning to go to a lot of places you should buy some bland crackers to eat between each winery. Dont feel like you have to drink the whole sample you get, they wont feel insulted if you dump the remainder. You will get at samples of at least 4 different wines and if you are planning to go to a lot of places, you could get drunk pretty quick or get sick of the taste. Also, dont feel obligated to buy from every winery you go to because that can add up.
If you are getting into wines, my friend suggests bringing a note pad and writing down what you like from what winery. That way you get a better idea of what you like (red vs whites) and you know where to get it the next time around.