I just started playing GW again but i have some questions

I, took a long break from guild wars, havent played since October 05.

So i am wondering, what has changed since then?
Is is still possible to farm? With Monk and what about farming locations any of those changed?

Has there been any major skill changes for the good or worse?
And any other major game updates?

And what does Guild Wars Faction add besides a new area and 2 new classes?

For farming stuff, check out the Class forums for that. Farming is still around.

There have been far too many skill changes since October to list them here. Go to http://guildwars.com/support/gameupdates/ and search around a bit.

Factions also added Titles, new weapons, new greens, new skills, new armor, new Guild Halls, Aliances... go to the above link. You'll find what you're looking for there.