How do you make sense of email headers?

For instance what does this mean?

Return-path: <[email protected]>
Received: from ms-mta-01 (ms-mta-01-smtp [10.93.38.11])
by ms-mss-01.texas.rr.com
(iPlanet Messaging Server 5.2 HotFix 1.12 (built Feb 13 2003))
with ESMTP id <[email protected]>; Fri,
05 Dec 2003 05:10:55 -0600 (CST)
Received: from txmx02.mgw.rr.com (txmx02.mgw.rr.com [24.93.41.201])
by ms-mta-01.texas.rr.com
(iPlanet Messaging Server 5.2 HotFix 1.12 (built Feb 13 2003))
with ESMTP id <[email protected]>; Fri,
05 Dec 2003 06:10:55 -0500 (EST)
Received: from belpsb.minsk.by (psych14.Psychiatry.McGill.CA [132.216.54.15])
by txmx02.mgw.rr.com (8.12.10/8.12.8) with ESMTP id hB5BAnDZ005842; Fri,
05 Dec 2003 06:10:52 -0500 (EST)
Date: Fri, 05 Dec 2003 07:19:16 +0000
From: Barney Oconnell <[email protected]>
Subject: check out free paris hilton footage
To: [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected]
Message-id: <NIEMMPFFLJIKMIIBLOPBONIAMOAA.barneyoconnelliv@arv ed.de>
MIME-version: 1.0
X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165
X-Mailer: Microsoft Outlook Express 6.00.2800.1158
Content-type: text/html
Content-transfer-encoding: base64
X-Priority: 3
X-MSMail-priority: Normal
X-Virus-Scanned: Symantec AntiVirus Scan Engine