I was just wondering what/where is the easeist place to gain exp in IWD?
I'm curently in the Vale of Shadows and i thought that monsters respawn? Was I wrong or is it in certain places only?

Any help/hints would be appreciated! =)

Hmm, that's a subjective answer. IMHO, the easiest is the Easthaven and the Orcish consortium takeover of the Merchant Guild

Yes, in the Vale of Shadows certain monsters respawn...the Lesser Shadows are always in the same place between the last crypt and the 5th crypt. If you rest, you can spawn the Yetis. Yetis are worth 300 xp and the Lesser Shadow is either 200 or 300. Not bad at the beginning. If you're in level 7 or more, then they are worthless, easy to kill, and worth not a spit for xp.

The game does get progressively more challenging and the rewards are exceptional!

Hope this answers your question.

Later on you will find cold wights when you rest in Dragons Eye. They give you 1500 exp and are easy as goblin pie. I would say unless you are having trouble getting past a certain point, don't rest for exp until you get to the cold wights.

The way I have gotten my PC's up in levels is this. Once they get enough EXP to to be up to about 3rd or 4th and have some nifty stuff (low AC and magic weapons). I start all over again with just one at a time all the exp you gain goes to one character and it adds up quickly. In easthaven you can go up a level if you do it with just one PC, there is about 6000 exp to be had there.
With the exp cap removed I have a Paladin thats up to 12th level. I recently started him in a new game going to see if he can do the whole thing alone or not.

Definitely, those cold wights are a gift. They have around 12 hp, and give 1500exp each, and they come in easy-to-use groups of 6-10! What fun!