The traditional Maibaum (maypole) is made like this:

take a tall pine or fir (the straighter the better).
Cut off all branches, remove the bark.
paint it in two spirals in white and light blue (hint: the colors of the Bavarian flag are white and light blue).

A weathercock is a nice peace for the top (but not absolutely necessary), but sometimes the top few branches are left there.

From the branches, make a wreath and use colored ribbons to tie it to the pole (near the top).

Now make the guild signs (usually each guild in the village makes its own sign - the baker usually a bretzl, the smith hammer and amboss, and so on).

These signs are mounted in pairs left and right of the pole on stakes that are stuck through the pole.

In many cases, the coat of arms of the village is added as well.

(in more modern times, as the guilds are vanishing, local clubs can put their signs on as well).

The usual date for erecting the maypole is the first of May.

No machinery is used for erecting except some stakes (always two stakes connected by some rope - the pole resting on the rope), just the muscles of all the young men of the village.
As gargoyle said, a maypole is placed in a hinge (nowadays steel in concrete, earlier on a wooden construction).

(I don't mention the tricky bits about guarding the pole, stealing the pole, freeing the pole ...)

Maibaum 1
Maibaum 2
Maibaum 3
erecting a Maibaum

MudGuard (from Bavaria, the place where the maypoles originally come from)