The hammer stapler just makes work faster on a roof so that you can get the tar paper tacked down and move on. Since I've also got a large garden shed in planning as well as a greenhouse, I figured it'd be a good investment. In loo of a hammer stapler you can use a standard one but really, it'd be just as well to tack it in place with roofing nails. So long as it doesn't have alot of wind to withstand.  
Cheep a'lil Talk a'lil :
And for the shingles, do you have to use roofing nails or any nail, with a fat head, that is galvinized (sp?) okay?
Use only roofing nails. Standard nails will not hold the shingles down correctly. A 5# box of 2" roofing nails runs $10 or so. Most nails with fat heads that are electro-galvanized are roofing nails.. 
 
Cheep a'lil Talk a'lil :
I'm stalled out right now and need to get a move on it.  I have everything I need to finish the coop except the motivation!  Maybe its the broken toe and the sprained ankle....don't know....
Well get back to work, slacker! I been looking forward to seeing what yours looks like done. Just smack your thumb with a hammer.. You'll forget all about your foot. 
 
Alright, alright, alright!  I'll get back to work.  I just need the allergy medicine to kick in!  My allergies are killing me, I can't see straight, I probably will end up hitting my thumb 
I checked out the staple hammer online at Home Depot, it was about $21.  And I could use for several different projects.  I think I'll have to invest in one.
I'm gonna have to get me a polish, yours is so cool looking, great coloring!
Well...I'll see how much I can get done after I mow today.  Probably will have to wait till tomorrow.  Mowing sucks the energy right out of me.