According to one of the links below, the technique was introduced by Hubbert in his 1982 review paper "Techniques of Prediction as Applied to the Production of Oil and Gas", which appears in the collection Oil and Gas Supply Modeling, edited by Saul I. Gass (published as NBS Special Publication 631). I haven't found this paper on the web, but I plan to peruse the microfiche version at the library of a nearby university soon.

There is a good introduction to the technique in Kenneth Deffeyes's book Beyond Oil: The View from Hubbert's Peak.

On the web, there's a great tutorial at Wolf at the Door (which also has a lot of other tutorial material on peak oil) and there's a piece by Jean Laherrère, which is a version of a paper that appeared in Oil and Gas Journal on April 17, 2000.

Stuart introduced the technique to the TOD community here. Interestingly, it appears that Stuart actually coined the phrase "Hubbert linearization" in this post that post. (It appears in the figure titles.)

If you know of any other references or links, please leave them in the comments.