Almost all Library databases can be accessed from off-campus. The easiest way to do this is to use links from the Library website. You will then be prompted for your CNetID and password to authenticate yourself as an authorized user.
If you find sources through Google Scholar or other search engines, you may not automatically get access to Library resources. Use the ProxyIt bookmarklet or Libkey Nomad in these situations. There's more information on these in our guide to off-campus access.