>As someone who knows very little about radio, how do I get into it?
Watch videos on youtube, get the ARRL books/study guides. Find a local repeater group/organization
>Does anyone have a graphic breaking down the categories and frequencies with their names and examples of a good piece of hardware?
Basically there are 2 categories. HF, and VHF/UHF. HF is what I would consider classic HAM, using AM, CW (Morse code) or phone, 10meters and above (below approx 30MHz). These are long range radios, you'll see Kenwood, Yaesu, etc. Big money radios, big antennas, etc.
The other type are your short range radios, like your Baofengs which are UHF/VHF (70cm/2m).
There are also 900MHz and above, but those are less common. These are your cheaper radios.
>For example, I'm under the impression pic related is a good entry level CB radio. Am I wrong?
>CB
Well, that's not a CB radio. It's a Baofeng UV-5R, which is a good, inexpensive dual band 2m/70cm radio. Great for making contact with your local repeater system. Cheap radios as cheap as $5 each on eBay.
>What is the difference between CB, UHF CB, and Shortwave?
CB is an unlicensed set of frequencies in the 11meter range. Similar to HAM 10meter, except with a 4w max power.
UHF, are higher frequencies - 300MHz to about 1GHz. They have high bandwidth, and are usually line-of-sight in terms of transmission.
VHF is below UHF, less bandwidth, better penetration of matter.
Short wave are just frequencies usually below about 10meters, but there is no exact definition.
>Which one should I get for emergencies?
I'd recommend getting your HAM license and get a cheap Baofeng. Even better if there are some repeaters in the area. Baofengs can also communicate with GMRS/FRS radios (your walmart walkie talkies) but it's probably not legal except in an emergency.
I took my HAM test a litle over a year ago and passed on the first try. A local guy charges $5 per test to take them. He also offers classes.