Rational functions are the hard ones of Algebra 2. In my current teaching assignment, I also teach them at the end of a two-year Algebra 1 class (which basically goes into Algebra 2). Here's what I'm currently using to supplement the textbook in my classes:
Designing Rational Functions which meet certain requirements - Again, I don't remember how much I changed the original file or even if there was an original file. Sorry about that.
There are some pretty fun graphs on Which One Doesn't Belong dealing with rational functions.