There are several things to think about with respect to photos and metadata.
1. The What: this is the elements of the metadata's data. The "Who", "What", "Where", "When", "Why and "How" of the photo.
2. The How: The technical storage of the metadata. Where is all of this data stored.
These two issues are discussed in their own child pages. There is a lot to say on each one.
In brief the What tries to answer the question What kind of meta-data should or can be collected?
Whereas the How tries to answer the question What should or can be be done with this meta-data?
File Naming convention: http://www.controlledvocabulary.com/imagedatabases/filenaming.html