[chef] Examples for newbies

[ItsMikeE < >]

I am finding it difficult to get to grips with chef.
There are just too many different ideas to get my head around at one time.

Is there some kind of Idiot's Guide to Getting Started with Chef?

I do not want to use the hosted chef. The servers I manage are not internet
facing.
I suppose I could create a hosted chef account and not have any nodes if that
will give me access to useful examples.

I have built a chef server and a couple of clients and I am now looking at my
first recipe / cookbook.

For my first noddy example, I want to set up two different versions of a 
config
file.
I have created two different versions of the file and stored them in
cookbooks/NAME/templates/default

Should I use ROLEs to decide which server gets which config file?
Do I do a test on variables or attributes? and how would I set these up (via
WebUI? or coding in the cookbook?)?

I can see the potential in chef, but feel that the various wiki examples and
the getting started guide are not pitched at a complete newbie like myself.

I am an experienced Sys Admin, but have no chef or ruby experience.

Thanks in advance