As an agent you have to hang you license with a broker. So you will be an independent agent working under the broker (head of firm).

You can do all the testing, but can not activate your license until you have a broker. In Maryland you have a year to do this after passing your test.

The test isn't incredibly hard. You just have to pay attention in the class. All of the material on the test will be covered in the class you take, and you will be given a book. Most of the time you will have to pass a test in the class before you can go on to take the state test. The class test will be harder then the state test.

I am licensed in Maryland, WV, and Pa and I passed all the tests the first time. You can go and take it again if you fail. The broker of my company had to take it 3 times.

In Maryland and VA you can not be licensed with any drug offenses on your record. It is different state to state. I have been told (though I dont have a record myself) from other agents that they dont check up on it. There will be a question on your licensing papers that asks about criminal record, but if you lie they wont know. They wont do a background check on agents, but if you ever go for your brokers license they will do a background check.

Check out these links.
Wisconsin Association of Realtors
http://www.wra.org/

National Association of Realtors
http://www.realtor.org/

I will say again that you need to go into this with some money saved up. For classes, licensing fess, membership to NAR and a local association (which will be required from most brokers), business cards, etc. you are looking at about 3 grand. You will also need money to live off of while you are getting set up. Even if you do a deal your first day you wont get paid on it for 3-4 months.