This should be pretty simple and something which I can't figure out instantaneously. So, resorted asking here.

Suppose, there is a sentence like this.

"Here is the documents needed" and "Here are the documents needed". Which one of it is grammatically correct and why? My guess would be second one because of the plural form.

On other note, if there is any correct guide/usage of plurals anywhere in a sentence, I can highly use it.