When researching online it is often difficult to tell if the content of a web site is accurate or not, so what ways do you use to determine if the web site you are browsing has correct information?

Thats a difficult question. Its like asking how do you know do you know that the man selling pepper in the market is sayin the truth? well one thing you cn doo is to cross check /verify the content with other sites (or sellers as the case may be ) u kno the Bible says, "in the mouth of 2 or three witnesses is evry word establishd" so when u see the same info on bout 2 /3 site that arent linked to each other, there is a great possibility that the info is authentic.
i hope this helps.

simple: you independently verify that the information you see on any site is true (or not)

how: as nduaj said, visit similar sites, check customer ratings, check to see if there are any complaints against the company (in the US, that can be found via the Better Business Bureau), ask friends/family.

In general, stick with established sites, no matter how expensive their product/service may be.

I hope this helps.