I recently was given a rusty Schrade Old Timer that was my Grandfather's years ago. I know this isn't a high-end knife by any means but I kind of like the size & look of the thing, and am interested in cleaning it up, possibly getting it in my rotation of EDCs.

I don't know the first thing about cleaning up old rusty blades, or if it's even worth the effort. Any suggestions for getting started on a project like this? Thanks! TK

Sounds like you're a logical fellow.
So I would think you would agree that about all you can hope to do is make that knife a bit more presentable.
Rust is the steel combining with the oxygen in the environment = iron oxide.
That iron is no longer part of the blade anymore.
It's gone.
And where it was is now a "pit" or a hole or slight depression, etc.
Without actually re-grinding the blade back to smooth, those little pits and depressions are there - forever.
But, we can clean off the rust a little.
Just basically get any rust "remover" off the hardware store rack.
A little steel wool, or scotch brite and add a bit of elbow grease.
Clean 'er up.
You might also try to find some sandpaper at least as fine as 1200, or better yet, 1500-3000 grit. You could clean the steel up a bit more.
If the knife is really badly rusted, don't get your hopes too high.
Enjoy what you end up with and carry it with pride.
Keep it sharp, and never let it get dull.