Buckmaster519,
Couple things. If you choose to hunt Iowa you will need to draw the appropriate tag for the zone your friend has ground in. As stated above this could take a couple of years.
Also, there is a difference in participating and assisting. You may observe (film, observe, ect.) but you may not assist in the hunt (Shoot, help carry weapon, treestand, help drag deer ect...). There are countless people that come to Iowa every year to film hunts and you do not need a tag as long as you are not assisting.
Good luck and to be safe just give the dnr officer in the area a call to make sure. It never hurts. But, you are well within your rights to film a hunt as long as you do not assist in the hunt.
I have waterfowl hunted in both Texas and Oklahoma and met some great people I hope you find Iowa folks as gracious.