to make my mother laugh.
How to: tell a joke. (This is like the Pirates' Code--guidelines rather than actual rules.)
-make sure you remember the punchline before you open your mouth.
-if the joke calls for it, do the voices.
-practice keeping a straight face. Or at least keeping your laughter to an intelligible level, so your audience doesn't have to sit there and wonder if you're going to pass out before they get to hear the punchline.
-remember: bad popsicle stick jokes are excellent!
-if you're going to tell a Helen Keller joke (or any joke within the category of "oh-my-god-why-am-i-laughing-this-is-so-bad"), make sure you know your audience.
Here are some standup comedians to keep in mind: Eddie Izzard, Dave Allen, Chelsea Handler, and Danny Bhoy.
There are more, obviously, but those are the ones I've nearly peed myself laughing at. Well, them, and Hasse och Tage (in Swedish only, sadly).