You can follow the steps given below to find out whether a website is trustworthy or not
1) Do proper research:
First you can to do a proper research about that site before ordering through discussions like face book or any other social networking sites page. You can check previous deals and user's response on them.
2) Read customer reviews:
Customer reviews is also very important. So you can regularly check for the customer review of a page. If you want to check customer reviews about a website you can visit this site Webutations.info here you can find out customer review about particular website and it's details.
3) Use whois lookup tool:
You can use whois information. Whois information basically provides details like website owner, contact details, email id, phone no. etc,. First you can check all of them whether the phone no, email id and contact details is legit and working. If it is legit, it is a good website and you can use that site. If you find the whois information is fake, don't make order or use the specific website be careful with them. If you need to have whois look up on a website, visit WhoisXY.com here you can get the full information about that particular website