TitoBob and MikeinRI are, in a sense, BOTH correct. Which point applies for you depends on how YOU are using the word.
The key is to see that there are two distinct uses of the word "scenery" --one of them can be used in the plural, the other cannot (though, in either case the form "scenery" IS a singular form).
The use of the word that takes a plural is actually the LESS common use --referring to a background set in the theater. You CAN refer to the "sceneries", by which you mean the sets for different scenes.
On the other hand, the 'normal, everyday' use of scenery to describe the general appearance of one's surroundings does NOT take a plural. ("I like the scenery in Virginia, Colorado and Alaska." NOT 'sceneries')
As for the special term - singular nouns which do not take a plural are called "non-count(able)" nouns. (Actually, there are also plural nouns without a singular, such as "news".) Examples: weather, furniture.
Notice that there are many nouns that may EITHER be 'noun-countable' and only used in the singular ("Have some more SOUP." "Is the BEER here any good?" ) OR, used in a slightly different way can take a plural ("What SOUPS are on the menu?" [referring to different TYPES] "May I have two BEERS." [meaning two separate servings of or cans of]
My advice - be sure you know whether the thing you are tallking about is being viewed as a "mass" or something else that is not counted, or as something to be counted. In the case of "scenery"/"sceneries" I suspect (unless you're discussing background sets in a play, etc) that you are NOT going to use a plural.
Some links with more on these "non-count" nouns vs "count" nouns, including many examples: