Each database interface will have its own quirks and shortcuts--be sure to check "Help" links if you get stuck!
Wildcard and truncation symbols can be used in many databases. They're especially useful if you don't know the exact term for which you want to search, or if there could be alternate spellings. Be sure to check the "Help" section of the database you're using, to make sure you use the correct symbol--it can vary.
Examples
AnthroSource database uses a question mark or a pound sign as a wildcard symbol. It uses an asterisk as a truncation symbol.
Bra?il will return results for Brazil, Brasil, and other variations which may or may not be relevant (eg Bragil).
Colo#r wil return results for Color or Colour.
Himalaya* will return results for Himalaya, Himalayan, Himalayas, Himalayans, etc.
