Cats are really easy to take care of, trust me I grew up with them, in fact I still have the cat that I got when I was 5, she is now 18 years old, she was 1 when we got her.
1) Keep in mind that they may not come when called, don't worry, they are all like that.
2) You only need to feed them once aday if you are going to leave the food out all day.
3) KEEP THE LITTER BOX CLEAN, sorry, this is a biggy, they will go on your floor, bed clothes if you do not keep the litter box clean. They like a dirty bathroom as much as you do.
4) If they mess on your floor, take them to the vet, there might be something wrong with them.
5) Cats are very clean animals, you will want to change their water every day. If they are anything like Tiger they will use the water bowl to wash their paws after using the box.
6) Have fun with them, make sure they have things to keep them occupied while you are not home. This will keep them out of trouble.