Self Service portal is mainly for capturing cases from your website or a public portal, like Web-to-Case (no authentication required) and aslo expose your Solution base publically. Use the steps below to enable/setup Self-Service portal in SFDC:
Setup-->App Setup-->Self-Service-->Web-to-Case (will let you generate the HTML to be embedded on your public website)
http://www.salesforce.com/crm/customer-service-support/customer-self-service-portal/
Self Service portal is mainly for capturing cases from your website or a public portal, like Web-to-Case (no authentication required) and aslo expose your Solution base publically. Use the steps below to enable/setup Self-Service portal in SFDC:
Setup-->App Setup-->Self-Service-->Web-to-Case (will let you generate the HTML to be embedded on your public website)
Setup-->App Setup-->Self-Service-->Public Solutions
Hope this helps! Let me know if you are looking for something specific to SSP.