In /etc/gettytab we enter after the lines
PlPclPc console: :ht:np:sp#115200: Here is an entry where lifestar is the username under which you need to login
Pc-autologin|Pc console with autologin: :ht:np:sp#115200:al=lifestar:
Then, in /etc/ttys, edit the line
ttyv0 "/usr/libexec/getty Pc" cons25r on secure
on
ttyv0 "/usr/libexec/getty Pc-autologin" cons25r on secure
And in the ~/.profile at the end add the line:
startx
To run for example kde4, then in ~/.xinitrc we write the following
exec "/usr/local/kde4/bin/startkde"