Okay, I'm creating a tutorial section on my site, and I wanted to provide JavaScript codes. Some of them belong to other sites (such as Dynamic Drive). Are there any JavaScript sites that will let me post them on my site for free, without getting written permission? They're the everyday codes, such as No Right Click, No Left Click, and etc.

Nope, no right click and other stuff is still made by a person and it is not general information. You must get permission first. If you see Lissa's site even the right click codes have written permissions on them. All you have to do is acknowledge to them that you are using them by a simple e-mail they'll probably ask you to put in a tag inside the code like this:

*/
Permission granted: bla bla bla
/*


People work hard on those scripts and I bet they would all appreciate knowing you're using them with them knowing at the same time.

there is one way to put JavaScript codes on your site without giving anyone else credit- write them yourself :)