One of the things we see every day are/is these abandoned houses right here.
One thing we need are/is books.
Are both are and is applicable here?
One of the things we see every day are/is these abandoned houses right here.
You will find many arguments on language forums about whether singular or plural should be used in this situation.
Some say "One ... is ... these houses.
Others say "things ... are ... these houses"
Personally I wouldn't write it that way - I don't like that sort of sentence.
One thing we need are/is books.
You will find people arguing about this too. However I strongly advocate using "is" in this situation. The subject of the sentence is undeniably singular and that is what determines the verb.
"One thing ... is books"