It's good to see a bit of interest in Ada. I really think it has some nice features to it that disappeared from languages that came after it (aside from some functional languages). I am mainly thinking of the type system when I say that.
I will be interested to see what you think of it once you get there.
Based on what I've already seen, I can say the Ada's type system is some kind of central part of the design to give tools for writing more reliable and safe software. I don't know of other languages which allow for so detailed “domain” definition through types!