All nordic ski racers do both disciplines, and most race weekends/carnivals will usually have one race of each technique. The exception to this being sprints, which are generally skate dominated. However, classic sprinting is catching on- there's a classic spring in Estonia on the World Cup this weekend. Good luck to Newell and Koos.
I think most people think skating is more 'fun', even though skiing either technique is still awesome. Personally, I like skating a little better just because you don't have to deal with kickwax/klister, but there's a lot to be said for a great classic day. Runners usually find classic more natural at first, provided they're provided with decent conditions and bomber kick. As the saying goes- classic is easier to 'learn' but harder to master. If you've been classic skiing, the transition to skate will be a little easier than for a totally new skier. Depending on your experience, your learning curve will obviously be different.
If you're particularly quick at learning and have good balance on skis, you may be able to use the v2 technique by the end of your first season. This is the technique used on flat and slight upgrades, but is too hard to describe verbally. Other techniques of skating are the v1, which is used for uphills (and lazy/exhausted skiers use this on flat terrain), and the v2 alternate, which is used for high speed flats, and cranking downhill. Watch other skiers or videos and you'll see all 3 techniques.
As far as gear...this may start a war here. A lot of people (myself included) like Salomon's skate specific Pilot binding system. NNN/Rossignol does not have a similar system, and some people find the Pilot binding keeps the ski in better control. I don't notice a huge difference between the Profil and Pilot bindings, but it is noticeable.
Boots obviously determine what binding system you get. Fishcer/Salomon/Hartjes boots use Pilot/Profil bindings, and Rossignol/Alpina/Atomic boots use NNN/Rottefella/Rossignol. Since you're more likely to notice discomfort in your boots than a binding system, choose your boots, then get the appropriate bindings.
Poles- longer than classic. The rough 'rule' for length is that the top of the grip goes to your lips.
Skis...personal preference. Fischer has the infamous 'skatecut' which is supposed to increase stability on hardpack conditions. I've never skied on them, but I've heard the Rossignol Xiums are solid skis. Whatever ones you get, make sure they're flexed correctly for your weight.
Workout intensity...about the same for each. All depends on the terrain and how much you like busting your ass. It is more difficult to skate quickly when you first learn, so technical deficiency will most likely prevent you from getting high intensity workouts in (unless you're going uphill).
Hope that helps and have fun with it.