re Buying wood at big box stores

Hey Mark
Some more random thoughts on this topic:
Whenever I buy any wood, from anywhere, including the local saw mills or
(shudder) the big box stores, I stack it with care in my garage with thin
straight sticks between each layer and at least 4" off the concrete
(stacked carefully- we call it "stickering" up here).  Then I let it sit
there for weeks- but what is important that all surfaces be exposed to the
air.  I want to reinforce the point made earlier that all wood must
acclimate to your conditions, so that means restacking it in your shop
before you start using it, and waiting... again.  Wood is hygroscopic in
moist environments, and releases moisture when the surrounding air is
drier; equilibrium is when absorption and release are equal, yada yada.  I
have a couple of moisture meters, but I never bother.
  When cutting parts on relatively fresh stuff, I always cut them oversize
and then let them sit for a while to do whatever they are going to do, then
I joint and plane the lumber to the final thickness and width.

   So if you remember that you are ALWAYS working on a moving target, and
that it's moving really fast when first drying out, but slowly breathing in
and out when at equilibrium, then you have the main point.

  When you do it this way, apart from the disadvantage of cutting stuff
twice I suppose, stuff stays relatively flat and stable pretty much forever.

   As far as glue goes, any of the modern glues have worked fine for me,
and I have had no issues with the regular  titebond.

  Going nuts with clamps is a bit of a rookie mistake, causing 'glue
starved' joints, especially if you have "glass smooth" surfaces.  I suppose
you probably have not run across a "toothing plane"?  They used to make
these to purposely rough up the surfaces before gluing ( especially for
veneering with hide glue) but it is a good idea for your application to
rough up the surfaces so that the glue has an opportunity to grab hold of
something.  You only want enough glue for a thin layer on both sides, and
just enough clamp pressure to get an even 'squeeze out', ie  a bit of glue
all along your joint. Good modern clamps can create very high pressures and
you can squeeze out all the glue if you crank them to the max, esp if the
surfaces are glass smooth. (You might want to look up a 'rubbed joint',
when no clamps are used at all- just rub the two pieces together to spread
the glue, no clamps... but this is not appropriate for your application)

Dowels can be tricky to line up perfectly unless you drill straight through
both pieces at the same time and then use a really long dowel pin.  I found
it easier to make a spline.  You can cut a 1/4" wide groove along both
sides, and then use a thin strip of 1/4" plywood as a spline between them
(sort of like a tongue in groove, but with two grooves and a free tongue).
For a workbench, it also adds strength to the joints, but the main thing I
suppose is that it helps you keep everything lined up nicely while gluing.
Cheers
Claudio In Waterloo