When you first start collecting world coins, it can be quite a challenge. Sure you first buy yourself a fat copy of Krause which is a great reference for identifying coins, but what about valuing them? Sure you can go for the local references, but aside from Canada, United States and more recently Australia (thanks to our Blue Sheet reference), what countries have reliable valuation references for certified coins?
The experienced collector will know that there is no resource more accurate for valuing coins than sales data, what better way to know how much a coin sells for, then to actually see, how much the coin sells for? Websites such as Heritage and Nobles offer sales data from their own auctions which I've always found to be useful resources (though it seems Noble's hasn't updated in a few years), also eBay allows searching of the past 30 days of sales, all available with free memberships but I've always found these methods very tedious, having to search through each site one at a time.
This is why I've created a solution at World Coin Sales Database - http://search.numismatics.com.au/. This allows me (and now you) to search sales history of any world coin (except Australia and the US, the former as I sell that data through the Blue Sheet, the latter as the US market is so big that the additional costs in hiring more data entry staff would be prohibitive at this stage, and that I don't collect US coins).
This database is a free resource, categorised by country and denomination, and ordered then by date. For example, say you were interested in valuing an 1892 Canadian 50c in XF40. You would navigate to 'Canada 50c', click it bringing you to this page: Canada 50c, then you would look down the list to see a number of sales for an 1892 Canadian 50c: