Good websites and/or books to learn game algorithms?

I'd recommend Realtime Collision Detection by Christer Ericson ( Director of Tools and Technology at Sony Santa Monica Studios - aka God of War ) - despite the title it covers a wider range of approaches than just collison detection including - data structures and algorithms for modern games development.

A lot of computer games coding is also simply good old-fashioned coding i.e data structures + algorithms so don't forget the two classics:
The Art of Computer Programming by Donald Knuth
Programming Pearls by Jon Bentley

There are also some excellent on-line R&D references on games development by many studios such as:
Mike Acton's Blog
Insomniac's R&D Site
Valve's site
DICE's site

I don't think there is any one definitive source for game development algorithms, there are so many different ways to approach game development even within a single genre.

The best advice I can give it to learn by playing with existing technology, get a hold of some game frameworks and go through their tutorials. I don't know of many for iPhone but you could look at the Torque Game Engine or Ogre3D for PC based technologies. Microsoft's XNA Framework is also an excellent starting point for console development. Any of those will give you a good idea of the basic structure of a game project and some of the core algorithms like pathfinding, collision detection etc.

If you'd rather read book though, I always recommend the Game Programming Gems series, last I looked they had six or seven volumes but they all contain collections of articles on all aspects fo game development.

Best of Game Programming Gems

There's some information atGamestruction which is a stack exchange based site, or you could ask this question there too.

You could try GameDev.net, DevMaster.net or Gamasutra for various game development resources.

There are various games development wikis including ones at GameDev.net and DevMaster.net and one at GPWiki.org