"I read book in my room" doesn't make sense in English.
You are however at liberty to say "I read a book/books in my room." These sentences are the same in English. The only way you can disambiguate is you you put "bir" in front of kitap to make it clearly mean "a book" :)
I would place a time clause in front of the locative, as the "natural" word order. For example "Her gece odamda kitap okurum." - "Every night I read a book in my room". This word order could be changed, though, if you want to emphasize the "every night" aspect: Odamda her gece kitap okurum.