Theoretically if someone had to quickly cover a hole in the roof with a tarp will a staple gun secure the tarp down well enough or should thin/long slats of wood be kept on hand to nail the tarp(s)in place?

-Blast

I would use the slats along the edges and interior sections or else the wind will negate everything.

I would definitely use roofing nails. The staples won't be able to hold it since they have neither depth nor tensile strength that is required.

Roofing or plastic capped nails, and wood strips. Staples will be a waste of time if you face anything more than a slight breeze.
If using just a tarp, if you can pull the tarp over the edge of the roof, roll the edge of the tarp a few times, and then nail from the soffit side through the rolled tarp, it will hold better than just nailing the tarp to the roof. A few wood strips nailed on top of the tarp will help hold it on.

and don't get real thin slats or the nails will split them--been there--done that--

If there's an actual hole, try to cover it with anything fairly rigid and tack it down, then cover with the tarp and strips. If you just stretch a piece of tarp over the hole, rain will tend to back up behind the lowest strip of wood and gather in the tarp 'dip'. If it's large enough, the weight of the water can either pull a piece of tarp loose, or a small piece of windblown debris can pucture it and it will split, allowing water to ooze through.

sue

We just did this. It was a hole from a branch, maybe 2".
Henrys roof tar from home depot, and an extra shingle.
They even sell some that can be applied in the rain/water.

Blast, the best thing for your roof in an emergency is to keep a roll of roofing (black paper) felt and a bag or two of similar shingles and of course the shingle nails and felt circular head nails. The reason I said this is during 3 hurricanes in fla, we had a old 3 tab roof and the 110 mph wind started stripping it off. During each storm that blasted through here I climbed up on the roof and put new felt and shingles back in to keep the roof from getting breached. The next hurricane came through and took off some more in a different location. After all 3 hurricanes came through I ended up replacing 300 square feet of roof. We waited 6 months to get a contractor to replace the old roof (paid for by insurance) and never had any water breached through the 300 Sq Feet that was gone. The people I knew who just left tarp and wood planks had water damage and some led to mold. Trust me you don't want mold started in your house. Shingling is a lot easier than people make it out (did it when I was young as well as a carpenter)and in my opinion the best way to maintain the water integrity of your house until it can be re shingled. The cost is really not that bad and lasts longer than tarps. Ozone kills tarps. If your serious about protecting your roof, this is the best way I know to do it and your repairs restore the roof better than original giving you time to get a new roof or leaving that way with no water breaches.

Side note: It didn't take me long to do this while on the roof in the rain with a repelling rope on tied to a palm tree to keep me from sliding off the roof. It was the only way U could stay on it two story's off the ground, I looked like an idiot but we had the least amount of damage in the neighbor hood.

Falcon,

You know, that makes a heck of a lot of sense. If I'm going to be up on the roof anyway I may as well make it worthwhile. I'm assuming pictures of the damages were enough for your insurance comapny?

Thanks.
-Blast

The insurance man said I did an awesome job and cut us a check with no questions asked. I didn't want to tell him I did it when I was younger. The roofer offered me a job as well, but I think he was just teasing me. That's one job that I don't care to do anymore for a living. I gladly pay someone to do it now, I'm too old for that anymore.

Also the insurance company paid us for the felt and shingles and my labor because he said if I hadn't had done what I did, they would have paid a lot more in water damages and encouraged me to do it again if this ever happens again. They would rather pay the extra for you to hold it until the roofers get to it than tarp it and get water damage.

How about sandbags to hold the tarp?