Well, just last week I bought Civilization IV. I have only played up to warlord difficulty level so far, as that seems even matched for me, as well as played a few senarios. I have modified previous games in the past, but have not modified any civilization games up to date, and wanted to get started. I looked at the tutorials section, but only saw details on creating #D units, which seems a little complex for me at the moment... so I wanted to start off with something easier. I was thinking about creating new resources and terrain types to add into the existing default civilization terrains and units. I'm not looking to change the exising resources and terrains(unless I can keep the new ones and the old ones). Is this possible? well I know resources are because I saw Cotton in the Chinese scenario. Can anyone help me get started?

First off, welcome to the CFC. :D

For what you're looking to do I'd try this oldie, but a goodie tutorial (http://forums.civfanatics.com/showthread.php?t=153584). I know he talks about skinning, but he also goes into the XML as well.

Good luck.

http://forums.civfanatics.com/showthread.php?t=144425

This was my first step in modding - it's really useful - it can be used for creating new nation or making interesting scenario wich contains natoins that don't appear in vanilla or warlords :)

I just opened the XML's and started changing stuff :p My first change were two new sealevels, none and flooded, which did exactly what they sound like.

Then I hopped straight into WWII Europe, but that didn't go too well.. too much too soon.
The best way to learn is either read the tutorials or just start finding stuff to change. The XML's are VERY easy, especially if you use XMLSpy or XML Marker.

Thanks for the advice everyone! I have no clue what half the stuff you mentioned is but the other half I do and I think I'll figure it out soon enough. Thanks for the great tutorial links!