What are my odds of getting 11B MOS?

I'm going to enlist in roughly a year or so and was wondering about 11Bravo MOS. I want to know how hard is it to qualify for and what do you have to do and say to a recruiter to get the 11B MOS. Also how hard is it to get 11B, and since you enlist with 11X what do I need to do to get 11B after OSUT. Also when and how should go about trying to get into Airborne school and maybe Ranger school. I want to be a paratrooper and i've heard that you can talk to your recruiter about being guaranteed a spot in Airborne school and you also have to ask him to guarantee you a spot in an Airborne unit or the Army will let you do Airborne and put in a non Airborne unit, I was wondering if this is true. The main point here is how and when should I enlist in the army so I'm guaranteed a spot as an Airborne qualified 11B with a guaranteed spot in an Airborne unit?