10 gallon tank will be more than enough for most species. Maybe a large species would need it turned on it's side.
I find the 10 gallon tanks we have some of ours in to be too large. The mantis hangs on the screen roof and doesn't care one bit about all the sticks in the tank. Also, it makes feeding crickets difficult because they just run around the bottom. If you use something so large then flying food is good or grasshoppers, because the hoppers will also hang from the ceiling.
If you go crickets, then go light on the perches and other furniture, so that the crickets can't hide too much.
You'll need a substrate that holds moisture.
And if you are in a very dry climate you can consider a water dish. Not for the mantis to drink from, but because it will also give off moisture.
Temp is likely not an issue, but look up specifics for your species. You can get a heat pad (sold for reptiles usually) but they are kinda pricey.
Make sure the lid is something the bugs won't get out of. The lids designed for fish aren't very bug proof.
That's about it. A jar to keep the mantis in while cleaning the tank. A bottle for misting that has never been used for any kind of cleaner, soap, chemical or anything that isn't simply water.
I like long tongs to pull out dead feeder insects with out disturbing the furniture.
Digital camera.
Consider a note pad for recording observations.
