Qualifications
To even be considered for one of only 3,000 or so special agent positions working around the globe, there are basic requirements that you must meet. The biggest duh of them all is that you have to be a U.S. Citizen (those easily surprised, please sit down and calm your breathing). You've got to have a valid Driver's License, because you can't really investigate crime from the back of a taxi.
A bachelor's degree with a minimum fifteen credit/hours spent on something related to finance, banking, or tax law is also needed. You must have a GPA of at least 2.8—get those grades up, C students. There's also an age limit of thirty-seven.
Wait, what? You read that right—there's actually a maximum age to join the IRS Criminal Investigation Division. Naturally, they will waive that requirement for people who already have military or law enforcement experience, but all you young college kids aching for a spot on the IRS team, there is a time limit, so get cracking.
In addition to the tangible above, there is the intangible "who," as in "who the heck are you, and what are you doing in my office?" The IRS isn't looking for just anybody; they're looking for people with analytical skills who can look at numbers and see patterns to get results. You're going to be on the beat, so you've got to know how to talk to people and get them to talk to you. You've also got to be able to handle the flack that comes with being the tax collector.