As I write this, Palermo has just hosted an international wine competition (even if Europe's best wineries usually avoid such "popularity contests" which they characterise as amateurish) and with Spring upon us it's time to think about travel to Sicily.
There's really no "best" time for a wine tour, though many travellers prefer early Autumn when the grapes are being harvested - well, late August in Sicily. What's important to keep in mind is the quality of your itinerary.
A number of travel agencies can plan a personalised itinerary, which is usually the best approach. Sicily Concierge is one such company, and there are others. Sicily's wine region is a good springboard for such an itinerary, while the Etna region offers a pleasant change of pace. Along the way there are plenty of traces of the past, such as Segesta's ancient Greek temple.
Do avoid the public relations pitching one winery over another, or a particular programme. It's easy enough to invent your own. Before you go, check out our Sicily wine page.