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I have the 430 EX and it's plenty powerful for home use. Now for the advice part: Learn to use manual mode on your camera, set the exposure for the background of the house (modify ISO, aperture, and shutter speed to taste), use the flash on ETTL, shoot, and then use FEC to bring up or down the flash as you see fit.
If you try to use AV as your camera mode with flash you may be frustrated, plenty of threads here and on the lighting forum for that.
In my experience, given a white ceiling, the best way to use an on-camera flash indoors is to bounce it off the ceiling. You can get nice even illumination that covers the whole room if it is a small home room, and you get great diffuse light without harsh shadows.
Obvious and standard flash use I'm talking about here, but just in case OP doesn't know it. You can mess with head tilt and direction to optimize it, but as far as exposure goes it is often best to just eliminate ambient light by setting your exposure to 1/200th, f/8, ISO 100 (usually does the trick in interior incandescent light).