Paul Brians’ excellent reference, Common Errors in English Usage, is available online.
An example:
LOSE/LOOSE
This confusion can easily be avoided if you pronounce the word intended aloud. If it has a voiced Z sound, then it’s “lose.” If it has a hissy S sound, then it’s “loose.” Here are examples of correct usage: “He tends to lose his keys.” “She lets her dog run loose.” Note that when “lose” turns into “losing” it loses its “E.”
Brians, 2008. Common Errors in English Usage