Most, but not all, survey companies have a feature in which members can invite their friends, therefore if you receive such an invitation from a person you know you can trust then by all means go for it.
Also you could give the old-fashioned Google search a try for making money doing surveys but as is well known, Google searching usually leads to more confusion, simply typing in "Online Surveys" in the search box is only going to get you millions upon millions of hits.
A more straightforward beginning would be with www.surveypolice.com they have a list of all the legitimate survey companies, with a ratings section and a place to leave your comments.
The following is a couple of the better online survey companies:
Inbox Dollars - www.inboxdollars.com. You're paid $1 per survey and you're allowed one survey per day, you also receive paid emails which although it may not be much you're still going to read your emails aren't you?
My Survey - www.mysurvey.com - look like one of the best with points being awarded for each survey completed.
At $10 for every 1000 points it sounds drawn out but they are forever awarding bonus points, so it doesn't take as long as you think.
Finally you must remember you will not get rich doing online surveys and there a lot of companies who want to get their hands on your money instead of vice versa.