One big difference versus Windows is that, on the Mac, the menu bar is always at the top of the screen. There aren't individual bars for each window. Thus, even when a window is "maximized," it'll still be below the menu bar. That takes a little getting used to.
Closest thing to a maximize feature is the green button at the top-left of every window. That will expand it as large as it needs to be to display all the window's content, up to the limits of the screen of course.
Not sure about a getting started guide, really; I'll do a little digging and see what's out there.
And as for the mouse,
ditch that thing! Any USB mouse will work just fine on a Mac, scroll wheel and all. I use a Microsoft Intellimouse Explorer, ironically enough.

Holding the Ctrl key and clicking will simulate a right click, but having a mouse with a real right button's just easier.
(When the MacBook comes, it doesn't have a second button or a scroll wheel, but the pad does some neat stuff: With two fingers on the pad, it will scroll horizontally and vertically. And with two fingers on the pad, the button will right-click. Very slick.)
Have fun! I need sleep. I have to get up extra early for my deadhead home, since I have to check my #^C*ing bag. :angryfire