I've trapped and spayed/neutered about 15 feral cats to control the population and check on their health. I then support them by releasing them in the same area and providing food and water. As the other poster said, buy or borrow a live trap. You can get one at Home Depot
http://www.homedepot.com/p/Havahart-Large-1-Door-Live-Animal-Cage-Trap-1079/100336697
You're not going to catch the kitten by hand, unless it's a tiny one (like a month old) and very sick. You can google TNR (Trap, Neuter, Release) for a protocol to follow. Briefly, you need to first acclimate the cat to the trap. Prop the door open, and place a dish of smelly wet cat food inside (like Friskies -- it's not that expensive). You can start at the entrance and progressively place the food farther back. After a couple of days, arm the trap and put the food in the far back behind the trip plate. BE SURE to be around when you arm the trap. I sometimes sit in my car and watch the trap, or if I'm in the house, I'll leave the door open so I can hear the trap trip. It's somewhat loud because the metal door will bang closed.
IMMEDIATELY go out and put an old sheet/blanket on top of the trap to calm the kitty down. Usually at this point I rush it to the vet to get it spayed/neutered/shots/wormed/flea treatment/tested for FIV and FeLV. If you want to bring it inside your house and try to tame it down, put it in a small space like your bathroom and provide a dark box and blanket for it to hide in. Be sure to offer fresh food and water. Kittens are relatively easy to tame down. The older they get, the more difficult it is to socialize them. Although I've had surprising success with kittens as old as 4-5 months.
Let us know how it goes, and thank you for caring enough to try to care for it.
-A fellow cat rescuer.