Do you guys think it's best to just go straight into an MMA class and train everything, or to take up a martial art or two for a while and get good at them before tying it all together with MMA?
Find a (respectable) MMA gym around where you live and just go there. Most places teach seperate classes for a bunch of MA as well as actual MMA classes.
Try a bit of everything, then talk to the people at the gym about what they think you should start off with.
When you've tried the different MAs and you have to professional's input as well, you can focus on what you find interesting as well as what they believe make a good base.
I was boxing way before I knew of MMA, but when I first went to a MMA gym I started out with kickboxing and what some people call submission wrestling (Which is basically wrestling with submissions mixed in there)
These days all I do is BJJ because that's what I find the most interesting and it's more of a hobby to me now (Plus a great way to stay fit)
What I'm trying to say here is - Do what you find challenging and exciting, that way you won't burn out in the long run