1. Uses of ham radio in offroading, and advantages over CB, cell phone.
ham is great for basic trail communications between a group of friends on the trail, but it shines when you have a group of 15 trucks that span a mile and a half of the mojave trail like SCCX Xcursion earlier this year, communications from trail lead to tailgunner and vice verse were no problem while cb was fading out around halfway through the pack. Another example where ham is great are large xcursions we've had with multiple groups on multiple trails, the trail leaders from all the runs can have a dedicated frequency to contact each other on opposite sides of a mountain, country or the WORLD!!! muahahahaha...oh sorry, wrong thread
*ahem* but seriously, with the use of repeaters, some of which are linked together with the use of the internet.
One of the clear(pun intended) advantages of ham over cb is fm modulation, ham uses FM and cb uses AM. Just like your stereo, fm transmissions are much more clear with ham.
Power is another nice feature of ham radios, most mobile radios have atleast 50 watts, some with as high as 75 watts!! Power isnt everything though, because of the higher frequency, even a handheld with a peak output of 5 watts and an external antenna, similar to the output of all CB radios of 4 watts, you can communicate long distances, much further than cb with reliability. With the use of repeaters, again, THE WORLD!!!
theres more but i think thats enough for now.
2. Necessary equipment for basic-level ham radio in vehicle
Like CB, a basic setup consists of a radio, antenna cable, antenna mount, and the all important antenna. For the new ham, you cant go wrong with a handheld, HT(short for handie talkie) with an external mag mount antenna, thats where i started.
unlike CB, there are many more options and features for radios, so it takes a bit of research and i recommend reading reviews, and getting hands on a few radios to get a feel for what you think is important features you would like. price is another aspect that varies wildly, radios start out at about $150 for a basic 2m radio and go up to $1000 for a full feature, multi band radio with so much capability it makes my head spin.
3. Other steps necessary to use ham radio (license, training, etc)
GhostX(John) touched on this one very well with a paste from the SCCX forum, but i would like to add that there are many websites to take practice tests, and all of the questions on the test are public knowledge and are published with correct answers so its really a no brainer, even if you dont know what the answer means, you can still know the correct one.
4. Recommended brands, models, pricing to acquire #2
Again John touched on this and had very good recommendations. Icom, Yaesu, Kenwood are all good brands for radios, there are some chinese companies now selling very inexpensive radios (starting at $40) but i will hold my opinion on those as i view it like the great winch debate, everyone has their favorites, some get burned, others have no issues.
Ham Radio Outlet (HRO) is a nice place with many locations where you can get a hands on with different radios and they normally have helpful staff that can point you in the right direction.