Here in the Okanagan the snow is starting to fly and if you haven't already started, you may want to step it up a bit to finish your clear up soon.
Some people ask, should I or shouldn't I rake up leaves? Short answer: It depends on your preference.
Generally speaking you will be doing nature and your back a favour if you just leave the leaves be. However, there are exceptions. If you have rodent problems it might be a good idea to do a thorough clear up. I'm talking all grass and grasses cut low and removed along with perennials cut back according to type and debris cleared out. If you have trees with large leaves then definitely remove them from lawn areas. They can cause problems with grass rotting and dying out when covered in snow for the winter. ( I learned this one the hard way.)
Cutting back your perennials is another chore that should be considered as well. Most perennials do well with a fall cutback or at least a deadhead if unattractive. Consider leaving some species alone if they provide birds with seeds overwinter. Leaving hollow perennials stems on the ground also creates shelter for pollinators etc.
Want more detail about specific perennials? Consult this book by Tracy DiSabato-Aust. "The Well-Tended Perennial Garden". I can't recommend it enough.