I got the dinosaurs from Amazon but one of those Safari toobs of dinosaurs will work too.
I don't have any patterns or anything - I basically just made it up as I went along. I used the same basic ideas as Fun at Home with Kids though. LOTS of hot glue :) But it was totally worth it and it really holds up well to little boy play!
Here it is by itself
Here is with about ten dinosaurs (I will use the rest for gifts & prize box awards)
Here is a different angle and action shot as my son is closing the lid!
And this is closed. I covered the box in a sheet of duct tape so you couldn't see the hot glue through the clear plastic.