Fair market value is normally the highest price, expressed in dollars, that property would bring in an open and unrestricted market, between a willing buyer and a willing seller who are both knowledgeable, informed, and prudent, and who are acting independently of each other. This value is normally used when a hypothetical transaction is assumed to occur rather than an actual transaction. Typically done for charitable donations or estate and divorce equitable distributions.
Generally, if the fair market value of the property is less than $1,000, a member of the registered charity, or another individual, with sufficient knowledge of the property may determine its value.
The person who determines the fair market value of the item should be competent and qualified to evaluate the particular property being donated.
If the fair market value is expected to be more than $1,000, CRA strongly recommends that the property be professionally appraised by a third party (that is, someone who is not associated with either the donor or the charity).
If the property is appraised, the name and address of the appraiser must be included on the official donation receipt.
Here is a link to the Canada Revenue Agency pamphlet which helps explain gifts and income tax: