I decided to get my RE license to save on commissions in 2012 before I purchased my second property. I'm in California so things may be a bit different in your state but here is what I did.
Take the required courses online - This was easy but time consuming, I was required to be logged in and actively reading, taking quizzes, final exams, etc. on the course website for 135hr. This took about a month of daily dedication.
With certificates of completion in hand I registered for the state exam. I think my test date was about a month away. The week of the test I bought a crash course book on passing the state exam and spent 2 days cramming and working the practice tests. I passed the state exam no problem.
In California you are required to hang your license with a broker to act as an agent in RE transactions.
I found a low cost broker, 90/10 commission split that was ok with me waiving my portion of the commission on purchases and sales (He would still collect his 10% so he was fine with it). My broker dealt 100% through email and phone calls, there was no training or lead generation but he did provide transaction coordination services at no charge. The TC services were a huge plus since I wasn't familiar with the contracts and documents needed to execute a transaction. TC services usually run about $350 per file, affordable and extremely worth it if you are a new agent.
I made it known to all of my family and friends that I was available to represent them in RE transactions but did not do any advertising.
In my years as a part time agent I averaged $12,000/yr in commissions from friends and family and have saved about $60,000 on my personal purchases and sales. Annual expenses are less than $1,000 for the Realtor designation and MLS access. I am a DIY sort of person and willing to figure things out myself. My first few transactions involved lots or research on preparing contracts and the necessary documents for a transaction.
I have transitioned into being a full time agent now and love all things real estate.
If you have the time and are willing to put in the effort you can save a lot of money and maybe even make a little money too.
Best of luck to you!