there are sections on other text editors, but the MiKTeX and TeXShell instructions were what I used. For anyone who has already installed both and not made any other changes, this should be all that is needed (it's all I ended up needing to do, anyway).
To change the TeXShell configuration, in the menu bar, click Option > = Program Calls and change the following:
TeX: replace latex by its full path (i.e. = somedrv:\somedir\miktex\bin\latex)
DVI Previewer: replace yap by its full path (i.e. = somedrv:\somedir\miktex\bin\yap)