Things you have to know (copied from Enturb):

Get your lulz, but please know what you're talking about (if anyone asks, know what Operation Snow White is, who Lisa Mcpherson is, and generally why the COS is an evil POS), otherwise you are headed for EPIC FAIL:

In the Old Days, Anonymous got it's "lulz" by fucking with people. The way to
fuck with the CoS is to actually be an effective picketer, and actually know
your shit when talking to Joe Public.

You want to do it for the lulz? Think about how holding a sign that says
"Scientology Kills" and handing out flyers with information and links to
Xenu.net, Xenutv.com, Enturbulation.org, youfoundthecard.com and
whyaretheydead.net is going to completely fuck up David Miscavige's*** entire
fucking week. Imagine how completely pissed off and helpless the Scientology
leaders will be against you when you actually do something intelligent
and effective.

The CoS is pissing its pants right now. It's scared shitless because it
actually thinks Anon might be able to stop it. If some of you fucktards don't
smarten up and actually do things right, they'll just laugh it off and go back
to ignoring Anonymous.

And then where will your precious lulz be?

***(David Miscavige is the current head of scientology. He's short, has a
lisp, and a horrible temper. If people start protesting well, instead for being
internet retards, he's going to blow a goddamn gasket, and probably break down
crying. There's your lulz. Go get them.)

Know how to make a protest sign that is readable from far away and will convey a clear, negative message about the actions of the Corporation of Scientology. (Don't call it a "Church," call it for what it is--a Corporation.)

Some good slogans:

Religion is Free. Scientology isn't.

Scientology tears families apart.

Scientology Lies

Scientology Kills

Scientology isn't a religion. It's a Corporation run by GREED.

Scientology would be FUNNY, if it wasn't so SCARY.

Lermanet.com wrote:

The big thing is getting people to get up off their butts and DO
something, but after you have accomplished the hardest part, don't waste the
effort because you did not prepare on the easy stuff.. pleasee!!!

These guys need to PREPARE

they need picket signs than can be read from far away here are some images of
our pickets and signs

A picketer in Washington DC

1) Most of us have signs on a stick to get them above our heads

2) All the text is in BIGGEST BOLDEST lettering the shorter the message, the
larger the text the farther away it may be read by passers by.

Know the rules and follow them:

http://www.youtube.com/watch?v=-063clxiB8I

The purpose of the demonstration in a modern western society is to convey a
message to the public. In keeping with this objective, Anonymous has drafted 22
rules that Anonymous can follow in order to assure epic win and no loss of hit
points on your part.

Rule #0: Rules 1 and 2 of the internet still apply. Your
memes are not, at this juncture, something that the real world can appreciate.
Although meme speak between fellow Anonymous is acceptable, focus on the target
and keep it to a minimum.

Rule #1: Stay cool.

Rule #2: Stay cool, especially when harassed. You are an
ambassador of Anonymous. Although individuals trying to disrupt your
demonstration will get on your nerves, you must not lose your temper. Doing so
will harm the protest and tarnish the reputation of Anonymous.

Rule #3: Comply with the orders of law enforcement officers above all
else. Doing otherwise is harmful the demonstration as a whole and may
compromise your performance as a human being. Do not request badge numbers
unless you are being treated in a very abusive manner, as doing so will anger
officers.

Rule #4: Notify city officials. Most jurisdictions either
have rules about public protests, or would prefer to be notified that they are
taking place. Know the rules for your jurisdiction and abide by them.

Rule #5: Always be across the street from the object being
protested.

Rule #6: In the absence of a road, find another natural barrier
between yourself and the target of protest. Doing so will make it more
difficult for individuals hostile to your cause to come and harass you.

Rule #7: Stay on public property. You may be charged for
trespassing if you do not.

Rule #8: No violence.

Rule #9: No weapons. The demonstration is a peaceful event.
Your weapons. You will not need them.

Rule #10: No alcohol or pre-drinking. Violating this rule
may easily precipitate a violation of rules 1 and 2.

Rule #11: NO graffiti, destruction, or vandalism.

Rule #12: If you want to do something stupid, pick another
day. These should be self explanatory. Violation of these rules during
a demonstration will tarnish the reputation of Anonymous, harm the demonstration
itself and leave you vulnerable to attention from law enforcement.

Rule #13: Anonymous is legion. Never be alone. Isolation
during a protest marks you as a target for handlers who wish to provoke an angry
reaction from you and other hostiles. In keeping with this principle...

Rule #14: Organize in squads of 10 to 15 people.

Rule #15: One or two megaphones per squad. A megaphone is
helpful for maintaining the overall cohesion of a demonstration and spreading
your message. However, too many will confuse the public and render you hearing
impaired.

Rule #16: Know the dress code. Forming a loose yet
reasonable dress code for protest members will help to maintain cohesion and get
the public to take you bseriously.

Rule #17: Cover your face. This will prevent your
identification from videos taken by hostiles, other protesters or security. Use
scarves, hats and sunglasses. Masks are not necessary, and donning them in the
context of a public demonstration is forbidden in some jurisdictions.

Rule #18: DO NOT take ID or credit cards. This will prevent
your definitive identification in case you do something unseemly and get noticed
by law enforcement.

Rule #19: Bring water.

Rule #20: Wear good shoes. Following these rules will assure
your comfort during the demonstration. Keep in mind that demonstrations may
often be quite lengthy.

Rule #21: Signs, flyers, and phrases. Have yours ready. Make
sure that signs are large enough to read. Also ensure that the text on your
signs and your phrases are pertinent to the target of the protest. Finally,
prepare legible, uncomplicated and accurate flyers to hand out to those who wish
to know more regarding the motivations behind your actions.

Rule #22: Document the demonstration. Videos and pictures of
the event may be used to corroborate your side of the story if law enforcement
get involved. Furthermore, posting images and videos of your heroic actions all
over the internet is bound to generate win, exhorting other Anonymous to follow
your glorious example.