Hey Anomaly,
What kind of questions do you have regarding the game? Here's some general information:
Guilds Wars has a main campaign (Prophecies) with two side campaigns (Factions and Nightfall), and then one sequel to all of them (Eye of the North). Prophecies, Factions, and Nightfall are all on separate locations within the same world, hence why they're considered side-campaigns.
The game is different than other MMO's in that it isn't about levels but about skills and story. The level cap is 20, but it can take a while to get there still depending on your play style and campaign choice. Stat choices are infinitely refundable and just are easily re-allocated.
The world is instanced - you will see other players in towns, but when you leave town you only see NPC's and party members.
The main campaign has the most classes available - ranger, warrior, necromancer, monk, elementalists, and the other two have 2 additional classes, assassin and...some other one in factions, and paragon and dervish in nightfall.
Your character takes two professions, a main one and a secondary. Each profession has a stat that you can only access if it's your main.
There is crafting, but it's not similar to other mmo's; the only resources to gather are from mob drops and you turn those in to collectors who collect them and in turn they give you armor. Higher quality items can be broken down to give you mats to upgrade other equipment.
There is PVP - it is arena based. You can only use skills you unlock during the campaign. Once you get a level 20 character, you can make PVP only characters that start at level 20 and have access to the skills you unlocked.
You can play with others, or it's completely solo-able as you can take NPC mercenaries in place of other players with you.
If you get Eye of the North, you can display your in-game achievements there and they unlock bonuses for Guild Wars 2.
The first part of Prophecies is considered to take place "in the past" so to speak, so don't be discouraged if it seems restrictive. If you get to level 20 "in the past", you get a legendary title. This is pretty difficult and time consuming
I'm currently playing right now to get my bonuses for GW2, I'm usually on my character Saral Lenigol (campaign character) or Balthorn Lenigol (on his way to legendary title character).
Cheapest location to purchase any of the games seems to be Amazon.com
If you're looking for a free MMO that might compare to normal ones like WoW and eventually SWTOR, I would check out:
LOTRO (Lord of the Rings Online)
ROM (Runes of Magic)
FW (Forsaken World)
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