A good source of info is http://canadianwarrants.com/index.html

Warrants are fairly common with the TSX miners. A typical pp will include a share and half warrant, often at a price close to the current share price. The buyers sell the share and keep the warrant essentially for free, which is one reason why such pps cap the share price until the issued shares are sold off. As lawnbowler mentioned, warrants often have a lot of leverage, which at the present time is not so good. There should be some real bargains out there, though. For example, Quadra warrants are now 0.75 after trading as high as 12.00. Quadra itself is trading in the 7s after being as high as 27.