Praying mantids are very easy pets to take care of, and are very rewarding in return ( AKA a very interactive pet.)
And I mean come on who doesn't want a awesome flying predator bug as a pet ? :D

Before I get a thousand comments saying owning a praying mantis is illegal!
read this Snopes article
I also looked on the US fish and wildlife endangered species list and found nothing at all.

Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Dictyoptera (Mantids and Cockroaches)
Suborder Mantodea (Mantids)
Family Mantidae

Step 1: Finding and Catching the Mantid.

Finding the mantis is the hardest part, but it is also the most fun, so grab your ipod and get outside.
You will want to look in tall grasses, flowers, small shrubs, short trees, pretty much anywhere lots of bugs are. The best time to find a mantid is late July to first frost (this is when they are big enough to find and are out of hiding to mate)
Don't worry if you cant find one you can buy mantis egg/ootheca at a good garden shop
or order a praying mantis here

Catching a mantid is very easy, all you need is your hand (or a stick) and a jar with a lid that has holes in it, or another container of some sort .

Do not grab the mantid it will bite you (It hurts really bad), let it walk onto your palm.
If the mantid has wings you will need to "shield" it with your other hand so it doesn't fly away.
If you are afraid of picking it up use a stick to gently corral it into a jar, put the lid on carefully so you don't catch one of its legs.

Step 2: Faking the Habitat

If you want your mantis to be happy/healthy you will need to copy his or her environment.
here is a list of mantis species if you want to look up your mantid
supplies needed
A cage at least twice as wide and three times as tall as the mantid. Glass aquariums work great.
A screen or plastic lid for the cage, plastic lids need air vents.
A ground covering such as mulch, pebbles,dirt, sand, or nothing if you want to see all the left over bug guts :P .
A light, nothing special a normal light bulb will work but It is easier just to use a aquarium light.
twigs,rocks,plants things to climb/molt on.
A water dish filled with pebbles or a small sponge or a small spray bottle with a mister.
A place to keep crickets this is what I used

Crickets smell really bad so you might want to keep them out side with a light bulb or heat lamp in the winter .

When planning your pseudo habitat keep in mind where you found your mantis, what it was on,
try to recreate its original habitat. It doesn't have to be too detailed the mantid won't know the difference any way :).
Another tip try not to make the cage too big or it will be hard for the mantis to find its prey.
Grass for the bottom of the cage is not a good idea unless you have the cage were it can get at least eight hours of non direct sun each day.

Step 3: The Cage

A good mantid cage should have several sticks and thick ground covering (1 to 2 inches )
some of the stick need to be horizontal so the mantid can hang upside down and molt.
My aquarium is forty gallons but that is over kill. :)
you will also need a lid home made or store bought it doesn't mater.(you really shouldn't have a solid lid it gets too humid and hot )

Step 4: Feeding the Beast !

Feeding your newfound friend is always fun to watch :)
(not for the faint of heart they are very messy/gory eaters)

How do you know its hungry ?
usually the mantid's eyes will turn from clear to black when it is hungry
(not always the case but it is a good indicator)
other than that mantids will pretty much Always eat

What do I feed it?
moths crickets butterflies grasshoppers ect are all good sources of food, if you get tired of finding bugs you can always buy them from a pet store (or mail order suppliers )
Buying crickets gets expensive real quick so I breed my own

How do I feed it ?
I usually put five or six crickets in a jar and pour them into the cage (carefully cause you don't want stinky crickets or moths all over your house )
if your mantid doesn't see the insect/s you can use a stick (or your hand) to move the food toward it.
if it still doesn't eat you can use a piece of small gauge stiff wire to impale the insect and "offer" it to the mantid (I had to do this two or three times before the mantid got used to the cage.)

All pictures and text is created by me unless otherwise noted

I will be adding more info as I get time so if you have any questions about mantids just leave a comment and I will try my best to answer them .
and as always constructive criticism is welcome :D
~Matt