Need to work up a price for a guy who wants a 12′ x 28′ shed roof w/ shingles built down the side of his backyard outbuilding.

Now the edge of the fascia is only about 7.5 ft high, but he wants the far outside edge to be tall enough to put a standard truck under.  I figure on making the bottom of the outside “plate” (which will 2x’s along 4x posts) 7 ft. 

I was thinkng I’d cut back the edge of the existing roof, nail my joists alongside his existing joists, sheath it with 1/2″ OSB and shingle.  That’ll give me a little slope, around 2/12 I’m guessing.

Question:  Will 2×8’s on 24″ centers span the 12 feet?  South Georgia – No Snow load, just pine straw.

And, does anyone have a good suggestion for a reference book to order to which I can refer to for planning roofs, floors, etc?

Also, I was thinking about getting “The Roofer’s Bible” or “Roofcutter’s Secrets” or whatever ya’ll would recommend on the subject. 

Anyone seen those Basic – Advanced Roof Framing Videos advertised in FHB every month?  I though about ordering some, but I don’t like VHS anymore – DVD for me, please.

All help is appreciated.

MikeVB