[KLF]

I'm a slow fussy bastid when it comes to interior trim work, so here's how I'd do it:

* Remove all the hardware from the jambs, apply first coast of stain. They can be stacked to dry.

* Install the jambs, fill nail holes, then quick second coat of stain. 2 coats of poly.

* Re-install the hinges & locksets, hang the doors unfinished, except for one. Stain & finish one door at a time on horses, horizontal. As you get each done, hang it in the jamb then move to the next one.

Curious to see what the "pros" on here would do...

I plumb the hinge side of the jamb first, using 3" screws, hidden in the hinge mortises. Then level the top, finally plumb the latch side, again sink a long strong screw hidden under the striker mortise. 2-1/2" 15-ga SS nails in my Hitachi gun. I hate split jambs, always use rabbeted style, much nicer looking.

A 6' level is your friend!