"They let me read this book because it is good."
Translation:Ellos me dejan leer este libro porque es bueno.
rspreng: Actually, there is although it is not used much. It is "ello". It is a neutral pronoun that can be used when speaking about "it" when you do not know if it is masculine or feminine. It is similar to "esto" and sometimes is tranlated like "esto" = "this", but it can be translated as "it". I have heard it used this way many times in Mexico.
es means "it is" — the
lo is not necessary (well... to be more accurate, it is not correct).
You would use
lo if you wanted to noun-ify an adjective. For example:
... porque es lo que es bueno= "because it is what is good"
Ahora Donuts: Lo rico de Castaño!= "Now, Donuts: The deliciousness of Castaño!", or a bit more literally, "Now, Donuts: That which is delicious of Castaño!" (Castaño is a convenience store chain in Chile).