a tutorial for light baking? you can google it, i guess. i don’t know of any particular or good or detail ones. (i never watched one. always “just do it” mentality, since source and hammer.)
the main pitfalls are lightmap resolution and mesh surface and lightmap matching. you gotta have continueous surfaces or it will bake seams where you might not want them. the rest is eyeballing your lighting and bake it. a couple times if you have to. normal lighting bake procedure.
you can use gpu lightmass to speed up the iteration process. the quality difference is what you gotta test yourself. or you bake the final version in cpu in the first place.