What is a good website for translators to look for freelance translation online tasks and jobs?

upwork is a good website for freelancers

I would suggest Upwork.com. The website has a friendly interface. You get to choose projects and negotiate the terms of a contract with clients. You also get the option between fixed-price and hourly jobs. 

Many websites are there for this purpose; just check or surf the Internet.

upwork.comonehourtranslation.comunbabel.com

I will give you an answer based on hands-on experience. I recommend that you check websites of companies and establishments that you think could need translation services. I would go for websites of companies that use the language pairs you are specialized in. Websites of NGOs, ministries, think tanks could be a very good option, but not guaranteed of course. Also, you could check websites of major translation companies that have good reputation, create an account there, attach your resume and cover letter, and wait for them to contact you, because they only contact translators when they have tasks matching your qualifications. I wish you a very good luck, Mariam. 

Yours, 

Belal ElOuri

https://www.protranslate.net/ar/

http://www.proz.com/

https://www.upwork.com/

https://www.freelancer.com/

http://cournal.com/

There are many online translation sites. These sites make it clearly that they are not responsible of the credibility of the customer, and they ask you to make your own arrangements to collect cost of translation. Accordingly it is difficult to recommend one. I hope those who tried some and received their money tell us too.