I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
harsh huarache huaracho
harsh marsh boorish rash boarish bearish arch rush qurush resh queerish garish brashy moorish nourish parish poorish sourish trashy whorish crush fairish brash marish frosh girsh crash currish gursh qursh fresh larch brush march marshy noirish parch perish search trash wearish cherish
haar hair hairy hare harrow harry hear hoar hoary