harv3034 said:
I know that there is a monthly subscription fee. But I don't know how much that fee is, and what other monitary investments are required.
http://us.blizzard.com/support/article.xml?locale=en_US&articleId=21450&parentCategoryId&pageNumber=1&categoryId=2324 <-- US subscription options (your profile says US)
I know that a new expansion is comming, but I'm curious if I would need to buy the original + all the expansion packs? just the original and Cataclism? or just the newist expansion pack?
Based on the other expansions no, you will need all of them to experience the content, but you don't need them all straight away, unless there's something you want from day 1 out of the expansions. I do suggest getting the battlechest though, as it's pretty cheap.
I've come to realize that there are different types of servers (PVP, PVE). I don't know what these stand for, or what the major differences between them are.
PVP = Player Vs Player - if you're in contested territory, anyone on the opposing faction can come up and fight you. Including anyone who's of a much higher level

PVE = Player Vs Environment - during normal questing you cannot be killed by the opposing faction, unless you "flag" yourself. You can "flag" at any time, but entering opposing cities (and certain towns) WILL auto-flag you. You can still fight players, if they're flagged, and do battlegrounds on PvE servers.
RP = Role Play. You're supposed to role-play on these servers, but there are a lot of non-RPing people on them. The people on them would appreciate it if you stay away if you're not interested in RP.
I also don't have any idea of how the alliance/guild/group system works on any level other than as a group of people of the same race.
Guilds are basically social groups - and people mainly form three types - social, raiding and PVP. Social guilds tend to be laid-back, and don't expect you to participate in events; raiding guilds are there to organise raids, and you will generally be expected to attend a certain percentage of the raids; PVP guilds tend to PVP a lot and may expect you to participate in premade battleground groups.
I suggest joining a social guild early on - you often end up picking up bits and pieces from people who've been playing a long time. Though there are a lot of useless guilds out there, so if you feel it's not working out, you can always /gquit.
(In the next expansion guild perks are coming - so you will get rewards depending on the level of the guild, and your reputation with them, which may colour you guild choices in the future)
For grouping, you'll mainly be doing so for dungeons using the dungeon finder, which will automatically group you up. For dungeons, you're usually fighting through groups of hard monsters and bosses, with one person getting the mobs to attack them (tank), one person healing (healer) and the rest DPSing (doing as much damage as they can to the mobs, without getting too much threat, and getting themselves killed

). WoW parties comprise of (up to) 5 people.
Hope this post helps
