As a wine writer, I get a lot of calls from colleagues who need some wine information either to set a mood or give a bit of authenticity to a scene. I usually point them to one of the online resources that I rely on.
To get information on a particular wine, I use WineAccess.com
This is a site with up-to-date pricing and availability data on just about every wine available in the country. It also brings together wine ratings from a variety of sources. They have a 'knowledge center' that lets you see research on individual topics. For industry-focused gossip, you can't beat Wines & Vines.
If you're looking for general information, I'd humbly suggest a book: maybe my own The New Short Course in Wine.