This is a somewhat different topic from my fence thread. I'm going to be
mixing concrete soon for setting fence posts. Any advice on how to mix it,
what goes in the mix, where to get the stuff from? Or any good websites on
this topic?

There are a lot of websites, but the basic mix for concrete is this:
2 parts "1/2 inch" stone or coarse gravel, 3 parts sand, 1 part
portland
cement, and just enough water to make it workable. The sand should
not be beach sand, as the salt will mess things up.

Portland cement is available, usually in 94lb bags, at any home center
or
farm store. If you are making a lot of concrete, get a local sand and
gravel
company or landscape company drop off a load of each. If you are only
making a small amount (setting one or two posts) just buy the bags of
premix, otherwise you'll have a partly used bag of portland cement left
over,
and once openned, it doesn't really keep (though I have had some luck
using a 5 gallon bucket with lid). If you are making a lot of concrete,
buying
or renting a mixer is a good option, but it's not really needed for
only a couple
of posts..

If you are using a regular square shovel and a wheelbarrow, put 4
heaping
shovels of stone, 2 shovels of portland cement, and 6 shovels of sand
in
the wheelbarrow, and mix while still dry. You can use the shovel to
mix
with, but a hoe probably works better. If you don't have space to
store a
wheelbarrow, there are also plastic mixing tubs, usually in the same
aisles
of the home center as the concrete.

If your ingredients are bone dry, they will use about 2 gallons of
water, but
they will probably already have some water in them, so start by adding
one
gallon and then mix thouroughly. Measure it, don't just guess with the
hose.
It can help if you make a hollow in the middle of your dry ingredients
to add
the water, and gradually work the dry ingredients into the wetter
center as
you mix. You should have a very dry stiff mix at this point. Add a
little more
of the water, like maybe a quart or so. Continue to mix. From here on
out,
the amount of water makes a huge impact on the consistency. Even a
cupful
can make a huge diffference. You're shooting for a mix about the
thickness
of canned stew--something that just pours well enough to get it where
you
want it, but isn't runny or soupy.

Bag mix is made the same way, but use the recommendation on the bag for

the amount of water. Again, don't add it all at once, you might not
need all
of it, only get it wet enough to be workable.

And last but not least, rinse all your tools off right away, or you
will have
crusty tools until you gradually (if ever) wear the concrete off of
them again.
--Glenn Lyford