I would recommend spending a little money on the remote control transmitter / receiver, since they are fairly difficult to build from scratch if you don't have any electronics experience.
Depending on home many things you want to control (I assume just a rudder?), you only need a simple remote. You could take a remote control toy (car, etc.) and crack it open and take the guts of the car (receiver circuit board, battery pack, antenna, and solenoid / motor into your hovercraft If you need to control a servo motor, then that takes a little bit more sophisticated receiver, although a lot of cheap plane / helicoptor toys now have small servos in them.
For example, http://www.walmart.com/ip/Air-Hogs-RC-SharpShooter-Red/16933009
Another option is to order a simple / cheap R/C transmitter / receiver from places like:
Robotshop (great store):http://www.robotshop.com/tamiya-2-channel-remote-control-box.html
A much more sophisticated option (and one that you could re-use for future projects) is to use a PS2 controller, with a reciever interface. That allows you a lot of channels of remote control. I used this one: http://cheapcontrolsystems.com/index.shtml
to make a 2/3 scale robotic / flying R2-D2 rocket: http://www.youtube.com/watch?v=s8QD3YoF ... 67&index=4
It's a board that lets you hook up to 12 servos, and control them with a PS2 controller (see robotshop for one of those). It works great, and doesn't take any electronics knowledge, just plugging in the servo connectors, and using PS2 controller key presses to "program" the servos to move the way you want. When I got the board, is was around $35. They seem to be out of stock right now, but check back later.
There are similar boards at robotshop. If this is a route you want to go, let me know and I can help you select one. Servos from robotshop are good too.
Let me know if you have any questions.