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.
redder rudder ridder redear reader ruddier reedier readier ruder redry rider raider rudery redrew redraw retear reutter rowdier retro rater retry radar retire retore ritter rotter rooter router ratter rioter writer rattier retiree rootier ruttier
badder dodder nodder codder budder bedder judder madder sadder kidder chudder redder adder mudder wadder shedder ridder udder shudder tedder wedder bidder odder widder ladder fodder rudder padder gadder rowdier seder deer kneader rider lauder heder needier tidier guider lewder weedier rudery bawdier gaudier seeder wider chider leadier dowdier deedier chuddar reedier shader nuder cheddar raider ceder powdery giddier moodier lader ruddier hider leader feeder needer woodier doer weeder reader powder bider dere dear headier loader louder hoodier lieder fader cider deader cyder gaudery voider faddier header ruder eider muddier doddery seedier siddur redear heeder beadier readier shoddier aider wader coder cheder chowder beader shadier shuddery
redd red uredia cred brede bred rued ruddy rudd reedy redo reed rediae redia rede ready readd read ired credo uredo