State of the art in 2014 and now regarded as a classic. Here are a couple of my favorite resources on the pre-trained vector method:

An overview of word embeddings and their connection to distributional semantic models [1]

Global Vectors for Word Representation presented by: Richard Socher of Stanford University [2]

Paper Dissected: “Glove: Global Vectors for Word Representation” Explained [3]

You can find my own detailed explanation in section 7 of this post [4]

Reference for the implementation:

Jeffrey Pennington, Richard Socher, and Christopher D. Manning. 2014 [5]