Can you give me some advise about buying a Mac computer?

OK - I know the real answer is DON"T

but

It's for my daughter and she needs a Mac, not a PC

So - first of all, where do you buy Mac's at? What are the options - good places and places to avoid?

And what advise can you give me on models and options? What is needed, what should I avoid? As always the objective is to buy a reasonably nice laptop for the least amount of $.

Thanks for your help, SH's!