TCM was very helpful, as were my local independent video stores and the video library at college.
but really i just went with what i was in the mood for.
i was lucky cause i had some friends who were really into the same kinds of things i was and this one guy had a huge library of films that we would just randomly search through and watch.
then i found directors i liked and went from there.

but largely it was just "can i watch a 3 hour movie with subtitles today? yeah, i can pull that off"