Build A Loft Bed Does Anybody Know An Easy Way To Build A Loft, Bunk Bed For A Preschooler?

Does anybody know an easy way to build a loft, bunk bed for a preschooler? - build a loft bed

I want to build a loft bed for my daughter for four years because he was so many things to its overflow room but can not afford what they sell. Approx. $ 2500! Anyway, I want it to size mattress can double and a small desk and shelving them to take. I'm pretty good, but not a master at the moment. I really appreciate any clue. What would be the best wood to use? Thank you!