help with dialup to the free IOL service is available on IOL's help page on their website: the password is "free" and the userneame is "free" - depending on the dialup configuration, other network parameters may be necessary in Linux, such as a valid DNS server.
I second the idea of going over the kppp tutorial - also in SuSE 9.1 YaST may help you configure the modem and enter account information. Keep in mind that a few winmodems still do not work in linux