Framing a porch roof is not for your average homeowner. I suggest you consult a professional contractor. If you have the knowledge to attempt this job, you will need the right tools, a couple of ladders and a helper. If you don't have a prepared area, like a concrete slab to build on, you will want to prepare that area beforehand. Find more instructions here about how to frame a porch roof
. http://www.hometime.com/Howto/projects/porch/porch_4.htm.