Introduce 3 Good Web Sites (in English)

Today, I introduce 3 useful web sites.
First, Google is one of useful web site because there is much information when I search everything. Moreover, when I attach images to my blog, it is very useful. I didn’t use it until I enter academic, but now I use it very well.
Second, Wikipedia is also useful. If I have words which I didn’t know, but my electric dictionary doesn’t have information, I use Wikipedia. It is not formal encyclopedia, but it has up-to-date information, so it is useful.
Also, CS100-Introduction to Computers is very useful web site because I cannot use computer very well, and I cannot remember how to use computer. Therefore, when I forgot information, I go there, and I check it. That is, it need for me very well. These are my recommendable sites.