I am also new to MMA but I've already been training for a year now. I would agree with all the other opinions with a few "minor" additions. First, definitely find an MMA gym that offers bjj as well as wrestling, boxing, and/or kickboxing/muay thai. I personally train bjj and muay thai but I started out with boxing. Make sure you shop around though not all MMA gyms are equal. Also, think about what type of fighter you WANT to be, cause after your first fight you will discover what type of fighter you NEED to be. For example, I had my first fight which was a Muay Thai and Bando tournament last month. I had been working on setting up kicks off of my punches and vice versa. But once I got tired, I resorted to pure boxing, it worked, but it wasn't the game plan. BJJ is a must in my opinion and wrestling because in MMA you WILL end up on the ground. If you want to be a striker you need submission and takedown defense, a ground fighter MUST be able to set up his takedowns, there are so many facets that I have yet to discover. But I love it and I say anyone with an interest in fighting should do it at least once in their lifetime so, good luck!
Boo! fight with Honor!