There are many words in the English language that readers and writers frequently confuse and misuse, such as affect and effect (those two often get me). If you’re like most of us and sometimes mix up homonyms, then check out Confusing Words, a site that lists frequently confused words, giving their correct definitions, as well as examples of the words used in sentences.
Only ten are listed on the front page, but you can search for words as well. I wish they had a list where you could browse all the words, since they say there are 3210 of them, but perhaps that’ll come some day.
Confusing Words also has a favalet, where, once you’ve dragged it onto the button bar on your browser, you can use it to highlight any word on a site that you find confusing, and after you click the button, it will be looked up on the Confusing Words site. You probably have to have IE, though, since it didn’t work on my FireFox browser.