First, the DSLrs I've looked at have a fstop range of 3.5-5.6. Is that it?
No, that is the largest aperture rating for that lens. f/3.5 is its max at the wide end and f/5.6 is the max at the longest focal length.
Most lenses for 35mm format have a smallest aperture of either f/22 or f/32.
Second, wht is a CPU lens?
couldn't tell you. I've never heard of that one. Where did you read that?
Also what is a SD/MMC media card vs a Compact Flash
SD and MMC are two different flash card types. MMC is newer, less supported and more expensive than SD. SD is typically used in smaller cameras do to its size while Compact Flash (CF) is the most common, has the largest capacities and is the most cost-effective.
Does it matter what format it saves pics in, i.e. EXIF/DCF/DPOF vs JPG or RAW. Which is better?
EXIF is not an image format. It is a standard for storing camera data in an image.
Raw is raw data from the cameras sensor and yields the best and most flexible results. There are many different flavors of raw (DCF is a raw format as is CR2, CRW, DNG, NEF, etc.)
Jpeg is a lossy format but is the most convenient and space-saving. That comes at the cost of image quality compared to RAW.
My article on image formats
goes into more detail.
Are all these digital cameras compatible to computers, meaning will I need to go out and purchase a special software to be able to view my photos on my laptop, I'm hoping my Windows XP is compatible too...oh boy
That all depends. All cameras can be connected to a computer (drivers need to be installed) and the jpeg format can be read on any platform. Raw data needs special software which comes with the camera even though that included software is typically junk. It'll get your feet wet though. There are free options such as RawShooter Essentials (dslr cameras only last I checked) otherwise you will want to buy something once or if you start using raw frequently.
If you want to edit your images (adjust contrast, fix blemishes, etc) you will need some editing software. Many cameras come with Photoshop Elements otherwise the GIMP is a free but clumsy option.