With so many hackers hijacking websites these days, what do I look for to show me that I'm not on a hijacked page?
First, there isn't any one bitcoin site, but hijackers often try to setup phishing attacks on cryptocurrency sites to get you to enter information they can use to steal your coin (as happened with EtherDelta this week).
Generally speaking, look for the green lock icon in your browser. If it isn't there, don't open continue. Best to also check the actual certificate by clicking on that green lock to ensure the certificate is from a well known Certificate Authority. Also generally a good idea to watch the twitter account associated with the site. For example, in EtherDelta's case they started tweeting about the issue pretty quickly once they were aware. And if in doubt, don't open it and tweat to the twitter account associated with the site just to make sure all is well.
If you see a "self-signed" certificate Do not open the site!