studying forms

[Square]

does anyone know of a website, or websites, that would help me learn more about musical forms? what i want to learn is, for example, what makes a mambo a mambo? something that would explain clearly (and hopefully simply, too) so that when i listen to a piece i can confidently say, yes, that's bebop (or whatever). i get so lost in many of the terms today, that i don't which ones are passing fancy and which ones are actual musical terms for something that can be defined clearly.

thanks