The top picture shows the warp threads tied to the front of what is called

an apron rod...it's a heavy piece of metal....then you need to separate the warp threads out so they will all be an equal distance apart before you begin to weave. I use thick pieces of woolen fabric as my header. The white thing across the loom is called a stretcher...it keeps tension on the fabric from side to side and helps with making better edges...but I still need some practice in that area! :-)