I built Joseph a bunkbed for his 4th(!) birthday. I don’t have much for gratuitous making-of photos, but here are a few of the finished product. Let me know if you’re interested in more detailed pictures (up close, joints, connections, that kind of thing).
Update: I made a video when I built a bunk bed for Joseph’s cousin, Bella.
The wood is top choice white pine, which you can find at your local Lowes/Home Depot.
I knew staining it would be a bad idea as Joseph would likely end up denting and marring it (he’s rough, and pine is soft), so I kept it the natural look, which I like quite a bit. And to help protect against fingerprints and such, I used this Minwax water-based Poly.