IMO the most important part is never seen, how the tar paper/tyveck/whatever the newest is applied to prevent water infiltration. If you are handy you can probably do it yourself without f-ing too much up. Prep work and trimming is 80% of the job timewise. A tape measure and chalkline are essential, a level not so much. Use a paper/tyveck cut to 1-2' and paper the corners from top to bottom. Use a level from the fascia board over to the wall and mark 1/2" below the level so that you can see the chalk line when you go to put the soffit trim on. Measure down from that mark to get your starter strip measurement and line chalked. Lots of times the fascia won't be level so doing it this way fools the eye. Do your levels around the whole house to make sure they line up. Apply your starter overlapping the foundation by at least a 1/2", then the paper the walls...remembering to tuck the paper under any paper that has been used around windows etc. Use butyl tape on window flanges and then silicone caulk on the inside when the jays are applied around the windows and light boxes, etc. Dripcap on the top of the window tucked under the paper/tyveck/etc. Use aluminum drip. I measure the corner posts and figure out where the flange will sit. I then chalk a line on the corners top to bottom so that I can see the line and match it to the nailing flange as I nail the post on, this keeps the corners straight. Sorry to bash, but most framers could give a **** about plumb and square. There's more but that will give you a start.
I like the idea posted above about trading skills. That could save some time, especially trimming the J's. Maybe ask for a consult on CL. If I answered an ad such as that I'd charge $65/hr and you'd be far ahead than if you tried by yourself.
Good luck,
Richard