For general questions you can try asking on the discussion boards. Experienced users can offer suggestions.
Or you can use the Help & Contact link at the bottom of the page to request a call back from eBay. Use the "Contact us" link and follow the prompts for your issue and you should eventually wind up on a page with a chat option. Choose that, and the last option that appears in the chat window -- use the "See more" option -- should be "Contact an Agent" to request a call-back if you are in North America.
If using the "Contact us" link takes you directly to the chat assistant window, you may have to enter some context dependent cues to get to the call back link.
