How exactly do the guild wars games work?

Like, if I buy the trilogy pack (with guild wars, factions, and Nightfalls) are those three seperate games? Where does Eye of the North come in? Anything you have to tell me would be great, thanks!
Stop Snoring

Prophecies, Factions, Nightfall are in effect 3 games although they are interconnected. You can start in Nightfall (recommended) and gain access via quests to Factions and Prophecies. So these games are called chapters of Guild Wars. Each has its own starting area.

Eye of the North is an expansion to all 3 chapters, so it does not have its own starting area. You have to start a character in Nightfall, Factions, or Prophecies and then bring it over to Eye of the North. Eye of the North is a fair sized adventuring area with a challenging storyline mission and quest chain and also lots of dungeons.

You can start with any of the 3 chapters, but only Nightfall will start you off acquiring and fitting out heroes to serve as part of your party of 8, which will also include 4 henchmen.

GW is a complex game, but you learn it all one piece at a time.

The three sepereate chapters can be stand-alone games or can be linked together as part of the same game on one account. I beleive the Trilogy Pack has one CD key for all three chapters, so you can't create seperate accounts for each chapter using that. (who would want to? - hehe). EotN is a true expansion that must be added to any one of the three chapters to function.

There are reasons to start in any of the three chapters.

Prophicies is a great starting point for new players that really love the story aspect and are not in a rush to get to elite zones.

Factions is a good starting point for those who wish to play Ritualist or Assassin, you can't start either of those professions in any other chapter.

Nightfall is a good start for gaining Heros and playing as a Paragon or Dervish, again unique to that chapter.

Each chapter, and the Eye of the North, has its own set of unique skills though there are also a number that are common to all chapters. To play in the later parts of the game you will most certainly require skills from each chapter.

Leveling up hapens equally fast in Factions and Nightfall but Factions has more locked doors that must be opened via completing storyline elements in order to proceed.

No rage meant by this, but this is completely and utterly subjective. If you ask me, the best place to start is still factions. By the time you're lvl 10 in NF, you're already lvl 20 in factions, and you are probably as far as arborstone.. If you wanna be fast, start factions, cruise your way to Kaineng City, hop to NF, get the heroes there, or better, go to EotN and get 3 lvl 20 Hero's for free (MOX, Vekk and Ogden) and you will cut through the game as a knife through butter.. At least, if you know what you're doing. If you're completely new to the game, Nightfall would be the best idea, since you will learn to know the potential of heroes better than when you approach using my tactic^^

Please lets not get into arguments about which is best to start in and we all have our views coloured by our preferences and our experiences whilst playing.
All of which is likely to confuse a new player.

Yes all the games are linked they can be played as separate games or linked together.
They were intended to be linked and it is important when installing that you install one and then add the others games to the same account.
Check carefully before you install so you know what your doing

You can start your experience in any of the games.

Prophesies is the oldest of the games it has a western or European feel to is though a fantasy one.
Slow character progression easy for a new player to learn the game.

Factions came next and is Asian in style this game added the Assassin and Ritualist classes so you have to start here to create one of those.
Faster progression to max level.

Nightfall came out next it is North African in style to my mind, this game added the Paragon and Dervish classes so again start here to run one of those.
Added heroes to the game "customisable AI help"

Eye of the north latest incarnation of GW and is an expansion to the series not a stand alone game you can visit eye from any of the other games.
It was intended that you be maximum level to play there but I believe you can access it at lvl 10 or above.

Ask if you need more info or are just not sure about anything.
Welcome to Guild wars

possible problems
because this is now an old game it can be hard to find other players to help you form a party and get through the game.
But since you will have 8 character slots you can start several characters and one in each game will give you an idea which one you like best.

There are frequent updates to the game so your computer may have a lot of updates to get through before everything is loaded.
All depends on your download speed.

note
The canthan new year ie Chinese/Asian New Year begins early February if you start a character in Factions you will be able to experience your first Guild wars festival.
I think it unlikely you can get a character from either of the other games to a point able to cross over by then.

It's good to play the whole of Prophecies once, it sets the back story for Eye of the North and the GW2 game.

Factions is alright if you have EOTN. Its possible for a new player to leave the island at 12-13 and really meet a brick wall in Kaineng proper.

I started the Trilogy edition six months ago and the EotN soon after. Currently I'm partway through each of the four, though I've found I'm hitting walls in some of the games, so I'm going to try going back to basics: sending my oldest character back to Kryta from EotN to finish the Prophecies campaign before attempting to finish the EotN storyline. EotN seems to be intended for level 20 at the minimum anyway.

I'm also going to send my ritualist back to Cantha to finish the Luxon quests instead of EotN, I think. At first I was roleplaying a little with my characters, six of whom I sent to the EotN -- I was trying to follow the timeline of events, so sending someone to the Eye of the North meant they wouldn't be returning to the other lands. But I'm gotten more relaxed about the timeline and now I'm just trying to finish the main quests.

Imagine the campaigns and the expansion as separate countries, with buying a campaign giving you a "passport" to that land. Once you have the pass, you can freely travel from one campaign to another. And do almost everything there (only the starter areas are skipped).

It used to be if you start in factions you can jump over to Nightfall @ Kourna and grind sunspear. Or you can start in Nightfall and do a few quests and not need to grind SS. (http://wiki.guildwars.com/wiki/And_a...hall_Lead_Them)

It's different now that they removed the requirement for foreign characters.

However, you still would need to level up Tahlkora, dunkuro, Koss, and Jin/Sousuke.

P.S. "When Nightfall was just released, even Factions and Prophecies characters needed to get Sunspear General to continue through the quest; however, this was changed after about a month and a half from release. "

I did that SS grind and I am very glad they got rid of it.

I think everyone hits a wall now and again, My mesmer hit one in the southern shiverpeaks so I played other characters.
6 months later I came back to the mesmer and it was a lot easier.
I guess I had improved my play abilities.

No one was more surprised than me when I beat the end missions of Prophesies Nightfall and eye using heroes and henchmen.
I had finished factions 4 times before I managed to complete the other games.