In versions of AfterStep prior to version 1.2, all configuration is handled in a single file. This is the .steprc file; it should be in your home directory if you're running these versions. New versions of AfterStep don't use this file, preferring the GNUstep/Library standard instead. See below.
AfterStep now uses a directory structure to handle desktop customization. Versions through 1.4 need a full set of directories in each user's home directory. In other words, you need to copy everything in
[AfterStepPath]/GNUstep/Library/AfterStep/
to
~/GNUstep/Library/AfterStep/
There were several changes to this directory structure between version 1.4.0 and 1.4.4; these changes are beyond the scope of this document. But for help configuring 1.4.4, see : http://www.via.ayuda.com/~smw/afterstep/configs/index.html.
The /GNUstep/Library/AfterStep arrangement is, admittedly, somewhat inefficient, because there are always at least two copies of everything on any system running AfterStep. As of version post 1.4.5, it is possible to add only those files which you have changed to the directory structure in your home directory, and everything else uses the default installation in /usr/share/afterstep.
The various elements of the desktop have been separated out, in order that they can each be customized independently. Look files and feel files allow you to customize the desktop in almost an infinite number of ways. Note that any functional changes you make in a look file (like adjusting the number of buttons that appear on a window titlebar) must also be reflected in a corresponding feel file: the "feel" handles how you interact with windows, while the "look" controls their appearance. This is handy if you want your windows always to respond in more or less the same way, but want them to look differently depending on the task you're performing, the machine you're on, or whatever.
You can. Use the -f switch to force AfterStep to read from a file. Please notice that not everything will work with your old .steprc file "right out of the box"; but if you like the old version that much, why upgrade anyway?
RedHat apparently includes a look-alike to AfterStep which is actually a hack of fvwm-2. It is not AfterStep, although some RH distributions also contain the real AfterStep. RedHat has, as of this writing, agreed to change the name of their "hacked" version, in order to reduce confusion, and include the real AfterStep in post 5.0 releases.