Disabling the "beep" - edit the "config" file, set:
beep 1
beep_chat 0
beep_msg 0
beep_notify 1

Setting the width of contacts list:
/set ncurses:contacts_size 12

Enable logging:
plugin +logs
set logs:log 2
set logs:path

Add a jabber session:
session -a jid:somelogin@someserver.pl

Set jabber session password:
session -s jid:somelogin@someserver.pl password somepassword

Open a new window for jabber:
/window new
session -w jid:somelogin@someserver.pl
/connect