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.
rain rainy ran rin rani rein roan ruin ruana ranee reign run rune wren renew rouen runny
ain fain vain cain gain kain lain main pain rain sain tain wain chain an in