don't use hollow box construction like that..they aren't very strong in shear..if you don't have a thickness planer there are alternatives, you can get a hand planer..Rigid Tools makes a nice one..(heh..Rigid Tools...) Another alternative is to use an old fashioned hand plane...there is a learning curve there though...but it is worth it...there is little more satisfying than shaping
materials with your hands..(I did sat "little more...")

I would also not recommend using nails in other than trim...either through bolt
using steel gussets or use mortise and tennon joints..the thing you want to avoid is movement in the joints..it only detracts from the movement in the bed..<WEG>

next time you are in a timber frame building, check out how it goes together..there are alot of alternatives....you can also dig around the net. there are a bunch of examples of some damned stout furniture and architecture out there...

I don't know your location so I don't know what other resources you have locally..pm me if you need help...