Greetings Labryinth,
Much has changed over the years, but you will still find many nice people in game. Your old characters should be there ready for you to use, and with some tweaking of the template and updating equipment you will probably be up to speed fairly quickly.
It seems to me that the best way to get to know the game is to spend a little time in new-haven (probably not a whole lot for a returning veteran, but it is a new town since you left... there is a guild or two that is set up to help new players and returning vets get their feet on the ground (@.# - We Die Alot! comes to mind) and once you are ready, they will refer you to guild that fit your play-style, or you can stay on and help others.
You might want to add a little more detail on your play-style so that potential guilds will know that you could fit in well. PVM? PVP? PVE? Crafting? full Combo?
Whatever you decide, I think Atlantic is the shard to be on. We have the biggest population and an abundance of available items.
Safe Journeys and Welcome Home!