Some useful wine investing resources:
decanter.com/collecting/investment
Decanter magazine's free online guide 'How to Invest in Wine' is an essential read for anyone considering adding wine to their portfolio. Easy to understand and filled with excellent tips, the guide features 10 sections, including a general overview of the pros and cons of wine investment, explanations of industry terms such as 'en primeur' (buying wines before they are bottled) and dos and don'ts of the trade. Written in July last year, some sections need updating, but as a general overview, it works well.
The Liv-ex Fine Wine 100 Index is the leading industry tracker of prices at wine auctions, one of the primary ways investment wines are bought and sold. Updated monthly, the index tracks prices for the most sought-after investment wines on the secondary market. Most of the wines listed are from Bordeaux, but burgundies, champagnes and other varieties are also followed. While access to the index is by paid subscription, the Liv-ex website also features an excellent blog that tracks price trends and analyses industry trends with graphs and charts.
wineeconomist.com