Telling good websites from bad ones is mainly a matter of experience, and you probably won’t even think about it unless something makes you suspicious. Try to be less trusting on the internet and you’ll be harder to con.
Always ask yourself who created the content, why, and whether it is still up to date. Is the source likely to be reliable, and if not, can the information be checked?
Trusted brands
In many cases, people trust websites based on the real-world reputations of the people behind them. Organisations as diverse as the Mayo Clinic, Johnson & Johnson, BMW, Sony, John Lewis and the BBC have established strong reputations offline, and this carries over to their online operations.
Trustworthy organisations often provide the names of company officials, addresses (sometimes with photographs of buildings) and phone numbers. They want to show there’s something tangible behind the website, and it’s not just an empty shell.
Bloggers can also enhance their reputations by providing background information. A few will need to hide behind nicknames, for obvious reasons. However, many more use their ‘About’ pages to tell you about their qualifications, where they work, and how to contact them via email, Twitter, LinkedIn, Facebook, and so on.
If they are willing to put their reputations on the line then - barring the obvious cranks - they are probably more trustworthy than anonymous bloggers.
Beware frauds, fakes and ‘haters’
If you are not familiar with an organisation’s website or its products, use a search engine to find out whether other people have had problems. Includie words such as “scam” or “sucks” in your searches - it’s a good way to dig out the worst responses. Bear in mind that the web has no shortage of ‘haters’, and most companies will have some. However, widespread negativity is a warning sign.
You should also watch out for some common online scams. These include charging for file-sharing software (eg Limewire) or browsers (Firefox) that are actually free, and selling fake anti-virus software - programs that pretend to detect viruses on your PC, then charge you for pretending to clear them up. Be wary of any deal that looks too good to be true.
The web also has fake sites that are not what they pretend to be. These are often promoted by spam emails or messages that contain obscure or unintelligible links - they appear to take you to a well-known bank, for example, but lead to a copy of the bank’s site instead.
They are ’phishing’ for your logon name and password so they can steal from your account. Some browsers warn users about suspicious sites. In Internet Explorer 7, for example, the address bar turns green if a website is verified, yellow if it could potentially be fake and red if it’s a known phishing site.
The web works because people can navigate around it by following links. This is usually safe because good sites check their links and will try to avoid sending you to a bad site. But remember, the web has no quality-control mechanisms and anybody can publish almost anything they like.
Taken from: http://www.bbc.co.uk/webwise/guides/good-and-bad-websites