We followed the links below to create our bed frame and headboard. The last link had some good tips that helped us.
My big contribution:
Use bolts to fasten everything together. Taking careful measurements I created a track for for the 2x4 spacer. This makes setup of the spacer incredibly easy. Then I put all three benches together and drilled 3/8 holes and used 3/8 bolts, washers, and wingnuts to fasten. This makes everything easy to setup and take down.