Ok let's tackle the whole "women get paid less then men" thing everyone knows is true. That idea is probably reinforced by the US. department of labor's study that says and I quote "Working full time year round, women made 19% less money than men in the US in 2010." However, there are always nuances of that study that are left out let me run you through them.

From that source, I quoted:

Users should note that the comparisons of earnings in this report are on a broad level and do not control for many factors that may be significant in explaining earnings differences. (See table 16.)

From the foot note in table 16: The comparability of historical labor force data has been affected at various times by methodological and conceptual changes in the Current Population Survey (CPS). For an explanation, see the historical comparability documentation provided at http://www.bls.gov/cps/eetech_methods.pdf.

From the source mentioned in the footnote: Usual full- or part-time status. Data on persons “at work” exclude persons who were temporarily absent from a job and therefore classified in the zero-hours-worked category, “with a job but not at work.” These are persons who were absent from their jobs for the entire week for such reasons as bad weather, vacation, illness, or involvement in a labor dispute. In order to differentiate a person’s normal schedule from his or her activity during the reference week, persons also are classified according to their usual full- or part-time status. In this context, full-time workers are those who usually worked 35 hours or more (at all jobs combined).

Coming back to the original source: Women in nonagricultural industries worked fewer hours per week than men in 2010. On average, women worked 35.6 hours per week, compared with 40.4 hours for men. (See table 21.)

Furthermore, From that first source I quoted:

In January 2010, the median number of years that female wage and salary workers had been with their employer was 4.2, compared with 4.6 years for their male counterparts. Among both women and men, tenure at a job was greater for workers age 45 and older. (See table 29.) (Data are from the January 2010 Displaced Worker Supplement to the CPS.)

So men had been with their companies longer then women had that year. If you stay at a company longer you tend to have more experience and are paid more.

Again from the first source:

In 2010, 5.4 percent of employed women held more than one job, slightly less than in the previous year. Multiple job holding rates for women have been relatively stable in recent years and remain below the rates recorded in the mid-1990s. The rate for men declined in 2010 to 4.5 percent. (See table 32.)

If you work two part time jobs and still work over 35 hours the study still counts you as full time. So you have more women working multiple part time jobs which end up paying less then one full time job.

So what do we conclude from all this? People who work less, are less experienced, and work two part time jobs make less money then people who work more, more experienced and have 1 full time job that pays well. The data is all there laid out for you.