I'll be happy to give you an idea of what playing WoW is like, as well as some advice for your fist character in the game.
First is obviously what kind of realm to select. For a first time player I'd recommend a PvE server; this kind of server is focused on the player fighting and defeating the monsters of the game world itself, with Player vs. Player (PvP) happening either in special areas (Battlegrounds) or when a player 'flags' for PvP by attacking a PvP flagged player (or healing/buffing one) or by attacking a PvP flagged NPC. By playing on a PvE server, you'll have the option of PvP, rather than being forced into due to the nature of the server. This will let you get the widest range of play-types without having to commit to one right from the start. Another advantage to a PvE server is that you can have characters for both major factions (Alliance and Horde) on the same account and the same server; PvP servers are restricted to one or the other per server.
Next is race/faction and class selection. There are many possible combinations, some better than others; but for a newbie I'd recommend just picking the combination you find the most interesting. I'll also add that the Ally/Horde jerk levels are pretty much the same on either side. Alliance has more players on most of the servers, thus there is both more competition for mobs and more readily available help for quests; with the Horde's lower player population, the opposite is true. Picking what faction you want is pretty much purely aesthetic. Also, don't worry too much about racials, but you might want to at least check
the WoWwiki site to get at least a basic understanding of them.
As for class, I would recommend Hunter for your very first WoW character. I often joke with my friends that "Hunter is WoW on easy-mode" :snigger: ; and it is. This class is the easiest to learn (but has enough depth) to be fun to play. You can tame Beast-type mobs for a combat pet (which means you'll not be killed as often as most classes) and will be able to track all but one type of mob on your mini-map (the exception is Mechanical mobs) eventually. This is a surprisingly useful ability since you'll be able to 'see' where mobs are in relation to you and thus avoid them, or move to attack them when you want; it also makes the 'kill-quests' much, much easier (it'll even display whether mobs are friendly, neutral, or hostile to you).
The talent trees for Hunter are also the easiest to learn and decide on. It basically comes down to what you want from your pet. Do you just want a meat-shield that's there to get hit and hold the mobs attention, or do you want a pet that's capable of taking a mob down all on it's own and with realitive ease? If you want the first one, which will put the vast majority of damage into your characters hands, you'll probably want to put the vast majority of points into the Marksman tree or Survival tree; if you want the later, go for Beastmaster. All this makes Hunter a very easy to learn class and will let you get right into the 'meat' of the game without needing a whole lot of skull-sweat
.
Other classes I'd recommend are Druid (gives you a nice idea of just what it'll be like to play just about all of the classes without having to make more characters); Paladin due to it's toughness; Warlock for it's pet; and Rogue for it's sneakiness. All of these classes are fairly easy to learn (though the talent trees might make for some frustration as you try to figure out what you want).
As for professions, I'd suggest picking a gathering/crafting combination that will immediately offer a major advantage to your character in terms of gear or consumable items. For example: Hunter/Shaman skinning/leatherworking combination offers easy gathering of most raw materials (you'll be killing a lot of beast-type mobs, thus having an on-demand supply of leather without needing to worry about the nodes that other gathering skills use to get raw material [mining and herbalism]). It'll also allow you to craft gear that your character can use, thus lessening you're dependence on quests and drops for new gear. Leatherworking does allow for the crafting of mail items as well, meaning classes that switch to mail at level 40 will still find it very useful.
Another example is Paladin/Warrior with mining/blacksmithing, with pretty much the same advantages as the previous example (with the exception of mining needing nodes to gather from [you can select to display any nodes near-by from your gathering profession on your mini-map]). Herbalism/Alchemy, or skinning/leather, are good for Druids; both work very well. I'd avoid Tailoring (this is one of two professions without a gathering skill, it relies on drops by Humanoid mobs for the main raw material) and Enchanting (also has no gathering skill and is a pain to work on, even for those with multiple characters since you need enhancing gear to make raw materials).
Now on to what's really important: Is WoW fun? The answer is: Yes, yes it is fun! Very fun, both for the casual players and the hard-core raiders. Whether you can only play for a few hours at a time, or can play for 6 or more at a time, you'll find that you can make measurable progress in the game. When I first started playing, most MMOs chained your progress to groups, meaning that you couldn't really advance without other players. WoW changed that by making the game so that you can get to max level without ever having to group with other players (you won't be able to complete all the quests, but you will be able to complete most of them). This means the amount of time you stand around looking for a group is reduced to a minimum and there is almost always something to do that you can do alone.
WoW has the broadest possible appeal to the different play-styles and player-types of any MMO I've ever played. It's easy to learn (but a fun challenge to master), it's easy and fairly quick to advance, and offers a large selection of things to do.