There was a time when the boom period of internet was there and many sites came into existence promising money to the online workers for the jobs done and in fact they paid also good amount for even the simple jobs. Unfortunately that boom is over and the rates of payments have also come down significantly. People who were getting $5 for an online job are now getting hardly $ 0.01 for the same job. Of course the reason for this downfall is twofold. First is the number of online workers have increased thousand times what it used to be long back and other is the remuneration rates have plummeted drastically as thousands of sites have emerged in internet to take advantage of the online earning potential. The advertising revenue is one main source of income and that is now distributed in a large number of sites making the earning very small. Anyway the point wise answers to the query are as follows -
a) There are hundreds of online sites that boast of providing income to the people even who have no knowledge of IT area like programming languages etc. These sites are basically data entry sites and survey sites where anyone can participate and work in a monotonous way to earn some money. For example if you complete a survey in survey site it would take half an hour and one can earn $ 0.6 to $ 2.50 depending upon the type of survey. Many housewives use these opportunities to earn some part time money from such survey sites.
b) For a common person there is no site which can provide a decent payment. Survey sites, data entry sites, and some other miscellaneous sites can provide a little bit of money if one does some monotonous jobs there. I can give one example of survey site that is SurveyJunkie which pays $1 to $3 per survey. You have to have a PayPal account and payout would be made only when you accumulate $ 10. There are sites where higher remuneration is there but it requires writing and editing skills and some other proficiencies. There is also tough competition there. Some of them have closed new registrations also.
c) There are many fake and fraud sites which lure the gullible people and ask for some registration amount and then simply dupe the visitors. One must be careful in that and only visit the site after checking in the internet about it in some good sites or do a Google search about good companies and only stick to them.
d) The data entry is the most common dumb job that one can apply and other than that there are some sites which give little money for playing games or viewing quiz or going through commercial emails etc. The amount is small and I would not recommend it for earning point of view. Some sites provide micro jobs also and one can do those tasks and earn $1 after completing a few micro jobs. As amount is small I do not think that they are lucrative.
Knowledge is power.