The first thing you should do is set the username Mercurial will use for commits. It's best to configure a proper email address in ~/.hgrc (or on a Windows system in %USERPROFILE%\Mercurial.ini) by creating it and adding lines like the following:
[ui]
username = John Doe <john@example.com>
[auth]
bb.prefix = https://bitbucket.org/foo/
bb.username = foo
bb.password = foo_passwd
frequent commands
hg clone http://foo.bar
hg add
hg rm
hg mv
hg ci -m"your comments"
hg push
hg pull -u
hg up
remove missing files
hg rm `hg st|grep -v pyc|grep -v swp|grep \!|tr '\n' ' '|tr '!' ' '`