I'm looking to try a new mmo, and i'm minded to try LOTRO.  My only concern is how much loading there is in the game.  I played turbines previous game, DDO, and though it had its problems, the thing that really killed tthat game for me were the loads.  Every door was a load screen.  The maps were tiny and had load screens between them.  To go into a tavern was a load screen, to go sell things you picked up was a load screen.  I just got sick of it.

I realize instancing requires load screens, but they went overboard. 

So i guess my question is how often does this game need to load?  And when do loading screens appear?

The game world itself has almost no load screens; you can leave the steps of Thorins hall and explore all of Breeland, The Shire, Lone Lands, North Downs, Angmar , Rivendell and the Misty Mountains....  You will see 1 load screen between Ered Luin and the Shire... That's it.

There are instances along the way both private and public that have load screens. This is just like WoW you step thru the portal or talk to an NPC and get a load screen into your instance.

The other place they use load screens is for entering buildings...  to cut down on lag in the cities they moved most  AH, crafting, and vendor NPC's indoors.

I leave it to you to decide if that is too much zoning.

The world is wide open - there are very few loading scrrens and none of them are intrusive, and you really can go from one end of the world to the other without any loading screens - though it takes nealry 2 hours if you're walking.  Middle Earth is HUGE

The fist 5 levels or so have a bit more instancing because they are in a different world from the main game. Other than that there will only be loading if you go into a building, dungeon, or fast travel. You could go from the shire to rivendell and never have a laoding screen fi you wanted to. And you can sell stuff to any vendor and there are plenty outside of buildings.

So in conclusion there is very little loading in this game. About the same as WoW except for entering buildings. They have stated they would like to in the future make it so this is not the case.

In my opinion LotRO is the perfect balance of Instancing and open world content. Think Turbine weighed the effects of 2 previous game AC and DDo and came up with this very polished balance. Think the next game Turbine does will refine this balance even more

As has been said, there is virtually no loading screens in the open world. 

There are instancing during the initial few tutorial levels after that the world is almost seemless.

Buildings have loads, but they are basically instant on a normal PC.  Its like open door walk in, count to 1 and you're in.

Or put it another way, I dispise loading screens with a vengence and I have no problems at all enjoying LOTR. :)

Loading screens = Buildings, Housing, AH, Dungeons, Raids, PvMP, newbie tutorial, instant travel and some other minor places.  The adventure world is seamless, such as, Bree, Shire, Rivendell, Angmar, etc.