Small/Specialty Presses

I'm just starting to get into collecting and plan on collecting reading copies and first editions of my favorite authors (well some, mainly Brandon Sanderson, and Jim Butcher). However, I'm also looking into the idea of collecting complete runs of small or specialty presses in the fantasy/sci-fi genres. I was hoping someone could offer some advice as far as how to go about locating such presses, and maybe even some suggestions of which to collect? I'm also new to actual collecting as opposed to simply hoarding, so resources on collecting methods, determining value, etc, would be appreciated as well.

so many books, so little time . . . simply put - collect what you love. If you might re-read a work, choose the most beautiful edn and, rather than wrapping it up, read it. There are many small presses doing wonderful work, though I can't think of any that are 100% worthwhile - complete collections (while fun) are seldom worth the effort

Look at Oak Knoll Press. They publish catalogs that often have many small press books.