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.
shader shadier shudder shatter shedder shuddery shoddier cheder chadar chador chider chadri chudder sheeter shouter shooter cheater chowder chatter shutter chattery chattier shittier shoetree cheddar chitter chuddar cheddary
beader kneader reader loader deader leader lader fader header wader shader lieder nodder beater kidder guider nadir feater neater giddier muddier later dere gaudery ladder hetaera lauder redear mudder budder sadder voider seder coder ruddier aider odder rudery needer ridder heater leadier shudder shedder moodier chowder cheder chadri chadar wider weedier wedder padder udder tedder dowdier dodder heeder badder seedier gaudier hoodier cider adder deer readier heder powdery hider rowdier gadder powder nuder headier tidier eater padri reedier bider hater chudder rater bidder ruder doer bawdier eider feeder fodder radar dater oater boater wadder codder bedder cater dear judder faddier gater padre rudder louder seater coater mater beadier madder cadre redder madre rider seeder raider ceder lewder needier deedier cyder doddery tater pater water weeder widder woodier chador cheater chider shadier shoddier shuddery
shad shade shadow shadowy shady chad shat shed shoat shod shoddy