You can achieve expertise only through practice. Data entry however is such a job that you can do from home on a full time or a part time basis and also make a decent living. The only thing that you need is a computer and an Internet connection.
Data entry requires speed and an ability to read properly to avoid typos. So we can infer that data entry might sound simple but it is not everyone's cup of tea. It requires deftness and ability to manage vast volumes of data. You can also make thousands by posting ads in certain sites and also by selling affiliate links. Many marketing professionals pay huge amounts to post new information on their websites. This is because they think that the process is time consuming and so they pay others to do the job on their behalf. You can also earn through advertisements and affiliate programs.
Many companies are in constant need of data entry operators as attrition rate in this domain is high. However, if you want to freelance from home you must look out for good pay masters. Some amount of research on the net can give you an idea about the companies or individuals who are reliable. You can visit some webmaster forums that are always searching for people who can deliver quality work on time. These jobs are also ideal for those who have retired from their professions, students, housewives and others who have an urge to be self-reliant and help their family-members battle recession blues.