I've done my share of April Fool's jokes in the past.  I've had plenty of them done on me too.  Sometimes they go too far.  Here are some rules not to break.

1.  Nobody gets hurt.  Have you ever pranked somebody with something simple, and then they get really hurt?  What a bummer.  We all love seeing the pam on the floor prank, but that can easily set up a costly hospital bill.  And, what if Grandma comes over first.  Yikes.

2.  When somebody asks if this is an April Fool's joke, you must immediately confess.

My wife broke this rule last year.  She told me her sister was coming to live with us and that she had told me multiple times.  I would have remembered something like that.  After about 5 minutes, I figured it was an April Fool's joke.  I asked her, and she continued to tell me what a horrible listener I was and that she was really coming.  So now I was pissed off all day.  Just before bed she told me it was an April Fool's joke after all.  I didn't laugh.

3.  Don't do it on your little kids.  My dad one time came back from Hawaii holding a paper bag.  He said he had something really special for me.  I was 7 years old.  I opened the paper bag and it was completely empty.  He said, "it's Hawaiin sunshine!"  I was pretty bummed.  So bummed, that I don't really remember what he got me.  I think it was a DVD or something.

4.  No serious lies.  You're fired!  We're moving!  Mom and I are getting a divorce!  I've found another lover!  You never know the reaction you might get, and for God sakes don't tell anyone that someone has died... yikes.

5.  What goes around comes around... worse.  If you're going to pull a prank, make sure you're ready to receive a worse one, and no whining when you do.  Everyone always tries to one up the other person.  Just keep your guard up.