Read Me First

This assumes you've yum installed IceWM.

Caveats

xterm is very, very hard to read.
Menus, labels, and text are oversized compared to the graphical elements of the UI.
I still can't find an easy way to select wireless networks.
$PATH appears not to be exported.

(Respectively)

Install a better terminal.
yum install control-center and tinker with the font sizes and/or dpi settings
When you log out of IceWM, select your wireless network through the Sugar UI, and then press ◆ ctrl + ◇ alt + erase to drop back into IceWM.

Taken from the OpenBox instructions

su
cp /etc/skel/.xsession-example ~/.xsession
nano ~/.xsession

...and the lines reading...

# Uncomment the following line to debug sugar startup problems
#exec xterm

...should be followed by...

icewm-session

Note: Use gnome-session if you prefer GNOME and provided you've yum groupinstall "GNOME Desktop Environmwnt" --skip-broken --exclude olpc-logos (yes, that's what I had to do to get GNOME installed).

Resist the temptation to uncomment the #exit 0, otherwise you won't be able to drop into Sugar when you need it.