This article is from the X-Men Comic Books FAQ, by Kate the Short (email@example.com) with numerous contributions by others.
There are two ways to get into reading the titles: starting with the
current crop of books, or starting with the origins of the characters.
If you're diving back in after a few years away, go to the core titles:
Uncanny X-Men, New X-Men, and X-Treme X-Men, which feature most of the
characters from the X-Men movie, cartoon, and older comics. Each of the
titles rebooted with a new creative team multiple times over the past
few years, so there are numerous good starting points. For New X-Men,
start with #114 or #127 (the "E is for Extinction" or "Riot at Xavier's"
storylines. For Uncanny, #410 is the reboot jumping-on point (the "Hope"
storyline). For X-Treme, either start with #1 or wait until #24. For
newer titles like X-Statix, Wolverine (restarted), and New Mutants (new
version), just start with issue #1 or the first collected edition.
Tons of color trade paperbacks (known as TPBs) exist that collect the
various storylines and crossovers from the various titles. If you missed
a few years, and don't want to spend the cash to pick up a title you
don't want to read, check out your local library. Many libraries have
purchased the droves of TPBs Marvel has issued since 2001, so your home
library may have some of them, and/or may be able to get them through
Inter-Library Loan. Just ask your local librarian--that person is there
If you're new to the X-Universe, the best way to learn who all these
people are and where they are coming from is from the back issues.
Essential Uncanny X-Men (only one volume) reprints issues 1-24 of the
original (Uncanny) X-Men in a large "phonebook-sized" black and white
paperback. The four volumes of Essential X-Men reprint Giant-Size
X-Men #1 and then Uncanny #94 through Uncanny #179, plus annuals through
Uncanny Annual #6. There are also three books of Essential Wolverine
reprints, which cover Wolverine #1 through #75 or thereabouts. Great
stuff for those just getting started. The Marvel Masterworks editions
also reprint early issues of X-Men in color, including #94-100, #101-110,
and 111-121, soon to be available through Barnes & Noble in TPB form.
Readers who left off before Giant-Size X-Men might appreciate the newer
stories in X-Men: The Hidden Years. Those stories are set during the
reprint years of the title. Although the title has been cancelled, you
should be able to find the issues in back issue bins. X-Men Classics and
X-Men: The Early Years reprinted old Uncanny issues, and are a cheap way
to pick up back issues without paying back issue prices (on the other
hand, you miss the letter columns, something desirable in back issues).
For the truly adventuresome, the book "Marvel: Five Decades of the
World's Greatest Comics" offers a large history of not just the teams
and the characters, but also the company itself. It's surprisingly
unbiased, considering Marvel's usually corporate jitteriness, but it is
expensive. Your local library may have a copy.
Above all else, be patient. The comics are based on over thirty years of
comic book history. A lot of that history is, unfortunately, somewhat
presumed knowledge to read the X-Men titles. You'll figure out what's
going on soon enough. In the meanwhile, enjoy the comics.