I agree with the above posters. You need a tripod and adding lights behind the camera is helpful.
I've assisted architectural photographers before, and lighting is always their TOP concern. But a pro camera can do a lot of things point-and-shoots can't, including wide-angle lenses and lighting control. Can you do a business trade with a new photographer trying to build a portfolio?
If you can't hire a professional, you can try to do it yourself, either by experimenting with the natural lighting you have or adding lights. Never use the attached flash. This is what I've picked up, though I'm sure there's a lot on the www that goes into more detail.
For exterior shots, time of day is key. Study the sun's path and go for when it's as straight on to the front of the building as possible. If your building's best side faces north, try for a lower-contrast day or a longer shutter speed near dusk. A blue sky and flowering gardens are very helpful.
If you look at a bunch of pro interior shots in decorating magazines, you'll notice the warm and welcoming photos are well-lit throughout the room. I like seeing all the room lights on and daylight shining in for hospitality shots, but your lamps and bright windows can force the camera to a faster shutter speed, making the dark corners even darker.
Once your camera's set up on a tripod, take a couple of test shots and look at them on a larger screen. Notice any dark areas in the photo (especially if your room has contrasting finishes, like a dark bedspread against a white wall). Then try to point additional bright lights (outside of the frame) into those spots. Think of it like billiards--if you can't get a light to shine directly into that pocket, bounce it off the wall behind you, or the ceiling, and it'll also soften the light. Also try to match the type of light bulb warm/cool, so you don't get a blueish spotlight in the photo.
I've seen professionals spend over an hour trying to get 1 photo just right. Patience is essential.
Good luck, and we look forward to seeing what you come up with!.