Google (c) can be used to search for many different websites pertaining to different types of information but for the best single sight you won't have to look far: your already there.
This website, which is Answers.com and WikiAnswers, is the best website for answers.
merriam webster
yola.comorweebly.com
I don't know of the best website, but dreamweaver is a GREAT web page design software.