The military is an honorable institution of the United States. Joining it should not be taken lightly.
The dynamic of the military changes over time. During the Vietnam War, the organization lost professionalism due to a lack of public support and a lack of able, quality individuals that were willing to join. Today, the military consists of an all-volunteer force, which means that forcible conscription (or "drafting") does not occur in the United States. A notable exception to this policy can occur when an individual who has broken the law is court-ordered by a judge to join the military if the judge believes that the organization can help the person learn to lead a more disciplined life. This does occur, but it is not common. What this means is that the military is not full of individuals that are content to leech money from the government in return for poor quality of service. Citizens of this mindset do exist in all sectors of the workforce and military, however. No connection whatsoever is being drawn here between individuals compelled to serve by law and those who have a lazy attitude. Indeed, many who were forced into the military have taken advantage of it and become distinguished servicemembers in their own right!
There are some similarities between various branches and components of the military, but there is also a vastly different flavor between the Marines and the Army, for example. Some of the general details can be extrapolated to various uniformed services, but the specific information here pertains to the U.S. Army. The Army is the largest of the services, and it does a great deal of the heavy lifting and conventional activities in wartime. It is the typical ground force occupier of the military. This general description, however, does little to unravel the hundreds of different careers available within the Army or the difference between its various components.
If you are looking to join the military, one of your first contacts within it will be your recruiter. Recruiters are available at local offices all around the country, and they are each happy to explain the military to prospective recruits. You should be warned, however, that although recruiters are not paid on a commission basis per soldier recruited (they are paid at their appropriate pay grade within the Army), they are still encouraged to recruit as many new soldiers as possible. Unscrupulous behavior is not really an issue, but you should understand that a recruiter is acting in the best interests of the Army and not necessarily yours. Therefore, information that the recruiter tells you can be easily misunderstood, and it will certainly help if you can find someone who is currently a part of the military and can confirm the information for you. You can find out anything you want both before and after the swearing in ceremony (which the recruits below are participating in at a basketball game), but your options become limited once you have signed your name on the dotted line.
The Department of Defense and the Army are not ruthless organizations, but you should understand the basic nature of the services before you enter them. Once you sign a contract for any service component, that contract is binding, and it is very difficult to change components. It is also impossible to quit duty from any component unless you are willing to ruin your life with a dishonorable discharge, or you have received an honorable medical discharge. The Active Duty Army reports to a specific location (a base or fort) for service every day. Active Duty soldiers are assigned to this base and a specific unit within it. The Reserves and National Guard are similar in function, but contain slightly different careers and flavors. The Reserves are federally administrated and consist largely of Combat Support and Combat Service Support units (these units typically deploy soldiers in "slice elements" or small teams). It is a much simpler process to transfer Reserve units. Guard units are more often operated according to the needs of their state, and transfer between them and between states can be a more difficult process.
Enlisted soldiers and commissioned officers each have different physical and job-related requirements, but there are some general physical and mental requirements in joining and maintaining good standing with the military. Soldiers must pass the P.T. test and excel at it to the greatest degree possible. This test consists of pushups, situps, and a two-mile run. Since the 17-21 age bracket standards are the most common ages for prospective soldiers, I will include those requirements. Male soldiers of this age must correctly perform 42 pushups in two minutes, 53 situps in two minutes, and a two-mile run in 15:54. Females must perform 19 pushups in two minutes, 53 situps in two minutes, and a two mile run in 18:54. The requirements change for various ages, and a calculator can be utilized here as a reference for questions: http://www.armystudyguide.com/content/army_board_study_guide_topics/physical_training/apft-calculator-online.shtml If the link does not work, simply type apft calculator into a search engine.
A military commitment consists of eight years at the current time regardless of the component, and deployment to a combat zone is a certainty at the current time. There is a signing bonus which varies with the career field signed for, the component, and other qualifications. Enlisted soldiers will attend Basic Combat Training, while commissioned officers will attend Officer Candidate School (OCS) or Basic Officer Leadership Course (BOLC). Both career fields often require hard work, but are rewarding in different ways. Military life is very stressful upon families whether the soldier is a member of the Active Duty, Reserves, or National Guard, because the soldier must frequently depart from family members. The tasks asked of soldiers can also be stressful, but many enjoy the lifestyle. There are far too many jobs (MOS--Mission Occupational Specialties) within the military to predict exactly what sort of work you will be doing. Your recruiter or a friend may be able to help you with these sorts of queries. http://www.goarmy.com/ also offers some general resources to educate you about the Army. What is not known and rarely advertised is that much of a soldier's labor consists of mundane work which is not always exciting.
There is honor present within the military that is difficult to find in any other organization, and there can be a high degree of pride from earning the right to wear and display a military uniform. If you know the risks, benefits, and realities of the military and are willing to comply with its standards, then you may find it to your liking.