Crossover works very well for a very limited number of applications; and so-so for lots of others. It often involves some tinkering to get working right. You shouldn't be planning to go the Crossover route unless you know 100% for a fact your software works properly with it, or you have no problem with searching the internet and scouring forums and messing around with settings to get your stuff working.
It's not that Crossover is a bad product, it isn't, it's amazing really; but it's not a one-size-fits-all thing.
Your other options are Parallels or similar, which will let you run Windows apps "from inside" OSX - convenient, high compatibility, and fair to good performance depending on what you are trying to run and how high your standards are; and installing Windows under Bootcamp - inconvenient (you have to boot into Windows to use Windows apps), perfect compatibility, and as good performance as your hardware will allow.
Mostly people use bootcamp for "serious" gaming and something like Parallels for productivity type apps where 3d graphics etc is not required.
There is a lot of info about all of these options on these forums, hunt around.
Good luck!
