Well "+" button doesn't really maximize the window.It "fits" it in you screen somehow.It's strange, yes.In many programs (like Mozilla), "+" works for maximization, but generally it's not the same as in windows.Of course there's a custom modification to put that in (like, in window$), but it's senseless.Using the right bottom corner you can resize all the windows as you wish.
And yes, they don't have a start menu.They have something similar, which is in the upper left corner of the screen.It's the "Apple" logo.But why to need a "start" button, since we have a dock ;)
If you have any other question, let me know, I can help :)