Read PEP 8 (Guido's Style Guide) and know that we use almost all the same style
guidelines.

Maximum line length is 79 characters.  78 is a safer bet, though.

Identation is 4 spaces per level.  No tabs.

Single quotes are used for all string literals that aren't docstrings.
They're just easier to type.

Triple double quotes (""") are always used for docstrings.

Spaces go around all operators (except around '=' in default arguments to
functions) and after all commas (unless doing so keeps a line within the 79
character limit).

Class names are StudlyCaps.  Method and function names are camelCaps
(StudlyCaps with an initial lowercase letter).  If variable and attribute
names can maintain readability without being camelCaps, then they should be
entirely in lowercase, otherwise they should also use camelCaps.  Plugin names
are StudlyCaps.

Imports should always happen at the top of the module, one import per line
(so if imports need to be added or removed later, it can be done easily).

A blank line should be between all consecutive method declarations in a
class definition.  Two blank lines should be between all consecutive class
definitions in a file.  Comments are even better than blank lines for
separating classes.

Code should pass PyChecker with no warnings.  The PyChecker config file is
included in the tools/ subdirectory.

Database filenames should generally begin with the name of the plugin and the
extension should be 'db'.  baseplugin.DBHandler does this already.

Whenever creating a file descriptor or socket, keep a reference around and be
sure to close it.  There should be no code like this:
  s = urllib2.urlopen('url').read()
Instead, do this:
  fd = urllib2.urlopen('url')
  s = fd.read()
  fd.close()
This is to be sure the bot doesn't leak file descriptors.

All plugins should include a docstring decsribing what the plugin does.  After
the decsription, the plugin should have a blank line followed by the line
'Commands include:' followed by a list of commands, one per line, indented two
spaces.  The setup script will depend on this format.

Method docstrings in classes deriving from callbacks.Privmsg should include an
argument list as their first line, and (if necessary) a blank line followed by
a longer description of what the command does.  The argument list is used by
the 'help' command, and the longer description is used by the 'morehelp'
command.

Whenever joining more than two strings, use string interpolation, not addition:
  s = x + y + z # Bad.
  s = '%s%s%s' % (x, y, z) # Good.
  s = ''.join(x, y, z) # Best, but not as general.
This has to do with efficiency; the intermediate string x+y is made (and thus
copied) before x+y+z is made, so it's less efficient.