First decisions when cataloging
What level of granularity are you cataloging?
What is the primary content at that level?
Language, image, sound, video, cartographic, other?
Which MARC Record Type will you use?
Is the content static or continuing?
Is it a monograph, a serial, or an integrating resource?
If continuing: which issue or iteration are you viewing?
Affects type of MARC record, rules for descriptive cataloging, when to create a new record, etc.