Probably the easiest site to earn money. Jobs that you do are pretty easy. From page liking with Facebook over subscribing to a youtube channel, making some comments, various votings, and some sorts of sing up offers. It's pretty easy. Earnings range is from 0,10$ to 3$.
Let me give you some tips related to microworkers, that are more than welcome.

1. Create a new mail, new youtube account, twitter, facebook.
2. Never use a password you already use for your personal needs. (Your mail, Facebook, Twitter, etc.)
3. Check the work you have done. If necessary, twice. Poorly done job will be rejected and you get a negative rate successes. (explanation is below)
4. Do all jobs that are available, only then you can get the most from the MW.
5. Make sure that the job has empty seats, or more precisely, dont  do the job if there is only one or 2 spots left.
7. Make yahoo.answears account, get to the 2nd level, it is not difficult. There will be jobs related to  Yahoo.

Keep in mind that you'll first week, two, have a limited number of jobs they can do. The reason for this is that when you do a job, it has a couple of hours to the exact week that you worked a job confirmation by the employer. As you work more and more, and your jobs are successful, of course, you will have an increasing number of jobs that you can do. After you have completed the first 20 jobs will be opened group HG Jobs. Here you can do all the work. The number of available jobs is determined by temporary Success rate. If it goes less than 75% you will not be able to work, until you increase rate. I personally go out a month about 100$, but that amount is after 2 months of work, so keep doing jobs!