But those bottles of wine are expensive. I think at the regular grocery store wine section, a riesling or... to me, a chenin blanc, are fairly sweet.
If you live in city with a good wine store, just go in and ask, and they will point them out to you. Some wine stores have long descriptions near the wine, to help you figure out what is special about one or the other. There is a nifty wine store in west Los Angeles called Wally's. Hmmm, I'll see if it's online; they may have some handy info.
Some wine stores have fliers or bulletins that list their favorite picks of the month. Trader Joe's has some wine with descriptions in their general bulletin, I think (it's been a while since I've lived near a Trader Joe's).
Here's Wally's -
http://www.wallywine.com
They have primo wines; haven't checked the site for descriptions yet - there are probably better websites for basic descriptions.
I'd google under Dessert Wines.