Literally it means "some notebooks".
In some places, though, it might also mean "some pals", but that's slang
unos cuadernos
"Una cuadernos" is not grammatically correct in Spanish. "Una cuaderno" would mean "a notebook" in English.
The correct sentence is: "Escribid en los cuadernos" And it means "Write in the (your) notebooks"
Unos pinceles is spanish for some paint brushes.
"Unos lápices" in Spanish means "some pencils" in English. The word "unos" is the plural form of "un" which means "a" or "an" in English.
Unos libros means some books, or a few books.
"Unos guantes" in Spanish means "some gloves" in English. The word "unos" is a plural masculine article used to indicate an unspecified quantity of gloves.
number 1
Translation: Some chairs
"Unos sueños" is Spanish for "some dreams" or "a few dreams."
notebooks
Translation: Sacad vuestros cuadernos OR Saquen sus cuadernos