By David Hill.
Does anyone know where I can buy this pdf?
Their site is now "shut down" and I can't find this book!

http://www.spiderworks.com/

They are shutting down, but perhaps you can bug them for a copy?
Maybe ask them to release it to the community if Apress doesn't pick it up?

Wish I could "bug" them but I have no way to reach them. =/
I just thought this book would help me tremendously in making my first tile based game.
I've checked a few sites with tutorials on tile based game programming but it's too much for me to try and translate it to Obj-C and Xcode.
Most of them are for flash too like AS 3.0

Tile based games don't have anything super-special about'em.

Mostly you need a file to store maps in.

For starters you could use a text file to store maps, like

----w-------t---------
----w-------t---------
----b------ttt--------
----ww-----tt---------
-----w----------------

w is water t are trees, b is bridge etc
(use a fixed width font for better alignment)

Then you need a parser to load back the data from the files.

I agree cocoa and objective c are tough for starters, I suggest using SDL with c or c++ (or blitzmax) if you're starting out.

I've read around and I got the part where you store the maps in a text file.
I just don't know how to load the file and replace the numbers with actual images so the reason for wanting that book.

One quick question:
If I had a tile based game with 1s and 0s (0 = walkable, 1 = wall/non walkable) would I need collision detection?
As far as I can tell, you wouldn't. You can make it so that the player can only move in the walkable tiles.

"Collision detection" doesn't mean any one specific thing. If you move/jump/teleport/whatever you want to call it, from the center of one tile to the next (instead of smoothly walking between the two), detecting that there is a wall that you can't walk into is a form of collision detection. A super simple one, but it's still the same concept.