Mara Jade was one of the most polarizing figures in the Galaxy. Some people saw her an interesting person and a strong role-model, and they wanted to have sex with her. Others saw her as an annoying bitch who ruined Luke Skywalker and the Jedi Order, and they wanted to have sex with her.
The Emperor had lots of hands. They did things he was unable, or unwilling, to do with his own hands. Mara Jade was one of his most useful hands. The Emperor took her when she was very young and trained her to use the force and perform other duties as assigned. Her most useful skill was that she could hear Palpatine through a telepathic link anywhere in the Galaxy. This was slightly easier than the many other forms of Interplanetary communication that were readily available. Mostly Mara was sent on assassination jobs, but occasionally she got to do other stuff like spy on Darth Vader, or seduce old men. She once killed a man, however, when he joked about the Emperor giving her a "Hand job." Eventually she was ordered to fo the Jabba's Palace and kill Luke Skywalker. She failed, and allowed Luke to go on his famous rampage. She dreaded turning in her mission report to Palpatine, but, fortunately, he was killed a few weeks later.
While she was relieved that she didn't have to worry about getting yelled at by a drunk old man, she realized taht she needed to find work. With the Emperor gone, the hand market wasn't very strong, so she sought a different line of employment. She eventually found work with he smuggler Talon Karrde. He was cool, but not nearly as cool as Lando. It was in this line of work that she came accross Luke Skywalker again. She was still deeply disappointed in herself for not killing him back at Jabba's Palace, so she figured she might as well finish the job now. She was confused and dismayed when Karrde pointed out that the employee handbook forbade revenge murders. She vowed to find a loophole.
Around this time, Grand Admiral Thrawn took over what was left of the Empire. Seeing an opportunity to return to an employer who encouraged revenge killings, Jade met with Thrawn and offered her services. She was disgusted to find that Thrawn double-crossed her to capture Karrde. Disgusted! Since she only knew two people in the enitre Galaxy, she turned to Luke for help. Even though she openly promised to kill him, Luke helped her because it was the first time a girl that wasn't his sister had talked to him. He really hoped Mara didn't turn out to be his sister. After a complicated plot involving clones, Mara and Luke saved everybody and Mara no longer felt the need to kill him.
As he did with everyone trying to kill him, Luke offered to train Mara as a Jedi, but Mara chose to train with Kyle Katarn instead, because he had a cool beard and a motorcycle. After that fizzled, she "pretended" to date Lando before ending up at Luke's Jedi Praxeum. There she hung out with Corran Horn, but didn't stay long- getting back to her important work doing whatever the hell it was she was doing. Anyway, she eventually ended up marrying Luke Skywalker.
By now she had become a Jedi, and took Jaina Solo as her apprentice. At the beginning of the Yuuzhan Vong nonsense, Mara contracted some crazy disease. Lando was a bit nervous but convinced everyone that he was clean. While she was recovering, Mara hung out with Anakin Solo a bunch since he was superfluous anyway. After her illness cleared up she discovered that she was pregnant. Again, Lando went out of his way to convince everyone that he had nothing to do with it. Mara did stuff, then gave birth to Ben Skywaller, then did some more stuff, then theYuuzhan Vong were defeated.
Second Galactic Civil War
A few year later, Mara was involved in the Second Galactic Civil War, which was more complicated than the first one, but less cool. Though Luke was pretty sure that Jacen Solo was becoming a Sith Lord, Mara figured it was just teen angst, and saw no reason to not let her son hang out with him. She realized she was way off right before Jacen killed her via a poison lawn dart he jabbed into her leg... unfortunately the Imperial Dynamo neglected to purge the toxins from her system due to years of attending LSD drum circles with the Jedi council which made her combat prowess rusty