When hunting for deals it's possible to land on a site you've never heard of. Before you start looking around for reviews to find out more about the site, you needn't even leave the page to ascertain whether the site you are on is "legit" or not. These red flags should send you fleeing from the site: - Misspellings. - The site's is poorly designed. - No contact information. - Products listed on the site have ridiculously low prices slapped on them. Should you see any of that, don't even look for reviews [because they can be faked]. Head the other way.
When finding a new site, you should look it up on google firstly. Reviews can be faked, but there will be a noticeable pattern in them, and you can notice the inconsistencies. Also, usually if it sounds too good to be true, it is just a scam. On sites which rely on sellers such as eBay/Amazon you should check the ratings. If it's a new seller with low to no ratings, you should think twice before buying from him. Also if the ratings are low or seems to have a pattern of people complaining, the same thing applies.
I will only ever shop from a website that I have either used before, or I have had recommended to me by a friend. This is the only way that you are ever going to know whether you can trust it or not, and I would never want to risk any of my own money on a website that I didn't really know. Of course, things like spelling etc can set alarm bells ringing when spotting a scam website, so this is certainly something to look out for, but be very careful indeed.
Those are some good things to look for. I rarely shop on websites I am not familiar with though or that have no reputation. I would be too afraid I would be taken. I prefer to stick to mainstream websites or those that I am familiar with.