http://www.sorcerers.net/Games/IWD/index.php

I found this site by accident and found that it has quite a usefull collcetion of Stuff.
Starting with Charakter Creation Guides, Walkthrough, Mods, Tweaks,...

Hope it will be usefull ;)

Yep thanks, it's a pretty known site for IW mods etc :)

And indeed for most if not all of the dnd games :)

Spellhold Studios is another good site.

I used PlanetBaldursGate a lot, but it's been taken down since IGN closed Gamespy. Apparent PBG was run by Gamespy. Sucks, because I found it a great resource.

While SP is a nice community and has a good collection of resources, their mod lists are about a thousand years old*. E.g. for IWD I see one, maybe two mods listed that I would feel comfortable installing today--the rest are outdated, have been superseded, etc.

You'd be better served, mod-wise, relying on the threads here or even PPG's modlist.

* This may be a slight exaggeration for effect.

The best walk-throughs/FAQ/info I've found for IWD is here: http://www.gamefaqs.com/pc/256221-icewind-dale/faqs
Haeravon's walk-through is probably as good as you will find without buying one of the commercially sold guides on Amazon, although I disagree with him about his party composition (a well-balanced balanced party is better in IWD, and taking less characters initially to start brings huge advantages for early leveling-up). I think the best way to play IWD (ie. to power-level) is to start with a single character, and add a new one to your party at the beginning of each chapter.