Thinking About Modding: Where should beginners begin?

I posted this over on the Mac sub-forum as I'm a Mac user and therefore I'd be modding on a mac. Here's the post:

http://forums.civfanatics.com/showthread.php?t=498797

Here's the original text, for those that don't want to click over to that forum:

Ok. I think I'm ready to try modding again.

I'm looking for someone who is experienced to simply point me in the right direction.

I should clarify a bit before I start:

1. I don't want to pay for any software.
2. I want to start by making "simple" mods.
3. I don't know what I'm doing.

I'm looking for a list:

1. What apps do I need?
2. What threads do I need to read on "how to mod" (specifically for the mac)

I have TextWrangler. I know, woppee, frikin' do. But hey, it's a start! I've already added the "mods" title to the menu screen and installed infoaddict, etc.

but I'm looking to take that next step and work on some stuff myself.

Thanks!