When staining "raw" wood one has to remember that any knot holes and "end" grains or cut edges will absorb more of the stain resulting in those areas being much darker and you can never un-do it.
With large grain wood such as
pine or oak the entire surface of the boards are subject to this problem.
So, unless you want the above described "effect", before you stain anything, buy yourself a quart of shellac and a quart of denatured (wood) alcohol and mix them together 50-50. Both quarts if a big project, smaller batches if needed. (mark the container and seal it tight, it will keep forever.)
Anyway, just give all wood surfaces a "sloppy" coat of it and let it dry (couple hours).
Then, either light sand (220 grid) or steelwool the surfaces smooth. Careful though, some finishes tell you not to use steelwool.
Note:
Most any new or weathered wood has tiny little "whiskers" that are almost impossible to sand off. Thus, the shellac acts like a "shaving cream" and firms those "whiskers" up and the steelwool will cut them right off.
That process seals all the surface area and the stain goes on nice and even. One should do that especially if they are going to paint the wood because the paint goes on much smoother and the next owner won't have any trouble stripping the paint back off.
WARNING: always do a "test spot/patch" where it is not readly visible.
