Back when ....
Before I owned a thickness planer I built many a book shelf out of Home Depots Red Oak 1" X 12" boards. ... actually 3/4" X 11 1/2". :smile3: If I need boards that width I would probably get them there now as well, since the mill is a good ways away. Just sort through them for straight grained boards.
I don't recommend Cedar for any indoor furniture since it's a very soft wood and will splinter readily, especially where there is a lot of hand contact like a bed frame and you may get some really bad splinters. JMO
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)