Hebrew Lexicons are similar to dictionaries, but they contain some of the variations and conjugations of a given word. There are two notable Hebrew Lexicons in the collection, the Brown-Driver-Briggs Lexicon (BDB), and the Holladay Concise Lexicon. The former is more substantial (but older) than the latter, though both contain most of the necessary information about particular Hebrew words. Both are organized by Hebrew roots.
The Brown-Driver-Briggs Hebrew and English Lexicon by 
A Concise Hebrew and Aramaic Lexicon of the Old Testament by 
Hebrew and Aramaic Lexicon of the Old Testament by Transliterated Hebrew Lexicon
A transliterated lexicon does not require extensive knowledge of Hebrew grammar and vocabulary. The lexicon is organized by transliterations rather than the Hebrew words.
Online Lexicon
Theological Dictionary of the Old Testament by 
The Dictionary of Classical Hebrew by 