diff --git a/metadatadb.py b/metadatadb.py
index 8ef6a00..2e92f1f 100644
--- a/metadatadb.py
+++ b/metadatadb.py
@@ -1,5 +1,8 @@
 '''
 metadatadb.py
+
+Everything needed to interact with the metadata database; namely SQL ORM objects, a context
+generator for the actual database, and a handful of convenience functions.
 '''
 import contextlib
 import collections
@@ -15,8 +18,6 @@ HASH_CHUNK_SIZE = 10485760 # 10mb
 _db_session_maker = sqlalchemy.orm.sessionmaker()
 _engine = None
 
-ImageData = collections.namedtuple('ImageData', 'UUID, sha1sum, filename, release_group')
-ReleaseGroupData = collections.namedtuple('ReleaseGroupData', 'UUID, name, platform')
 DatData = collections.namedtuple('DatData', 'UUID, name, website, version, image_list')
 
 
@@ -25,7 +26,38 @@ def _uuidgen():
 
 _SQLBase = sqlalchemy.ext.declarative.declarative_base()
 
+class Image(_SQLBase):
+    '''SQLAlchemy ORM class for ROM image metadata.'''
+    # TODO: Split filenames into more meaningful metadata.
+    __tablename__ = 'images'
+    id = sqlalchemy.Column(sqlalchemy.Integer, sqlalchemy.Sequence('image_id_sequence'),
+                           primary_key=True)
+    uuid = sqlalchemy.Column(sqlalchemy.String, nullable=False, default=_uuidgen)
+    sha1sum = sqlalchemy.Column(sqlalchemy.String, unique=True, nullable=False)
+    filename = sqlalchemy.Column(sqlalchemy.String, unique=True, nullable=False)
+
+    # TODO: Add many-to-one relationship to release groups.
+
+    def __repr__(self):
+        return 'ROM Image: id: %s, uuid: %s, sha1sum: %s, filename: %s' % (self.id, self.uuid,
+                self.sha1sum, self.filename)
+
+class ReleaseGroup(_SQLBase):
+    '''SQLAlchemy ORM class for release group metadata.'''
+    __tablename__ = 'release_groups'
+    id = sqlalchemy.Column(sqlalchemy.Integer, sqlalchemy.Sequence('image_id_sequence'),
+                           primary_key=True)
+    uuid = sqlalchemy.Column(sqlalchemy.String, nullable=False, default=_uuidgen)
+    name = sqlalchemy.Column(sqlalchemy.String, unique=True, nullable=False)
+    # TODO: Add many-to-one relationship to platforms.
+
+    def __repr__(self):
+        return 'Release Group: id: %s, uuid: %s, name: %s' % (self.id, self.uuid,
+                self.name)
+
+
 class Platform(_SQLBase):
+    '''SQLAlchemy ORM class for platform metadata.'''
     __tablename__ = 'platforms'
     id = sqlalchemy.Column(sqlalchemy.Integer, sqlalchemy.Sequence('platform_id_sequence'),
                            primary_key=True)
@@ -37,6 +69,7 @@ class Platform(_SQLBase):
         return 'Platform: id: %s, uuid: %s, fullname: %s, shortcode: %s' % (self.id, self.uuid,
                 self.fullname, self.shortcode)
 
+
 # TODO: This should go in the eventual romdb class.
 def get_file_sha1sum(filename):
     sha1sum = hashlib.sha1()
@@ -50,12 +83,27 @@ def get_file_sha1sum(filename):
     return sha1sum.hexdigest()
 
 def configure(db_path):
+    '''
+    Configure and initialize the database for the entire module.
+    Currently, only SQLite is supported.
+
+    db_path: Path for the SQLite database
+    '''
     _engine = sqlalchemy.create_engine('sqlite:///%s' % db_path)
 
     _SQLBase.metadata.create_all(_engine)
     _db_session_maker.configure(bind=_engine)
 
-def search(session, table_object, inclusive=True, **constraints):
+def search(session, table_object, **constraints):
+    '''
+    Search the database for entries matching the given constraints.
+
+    session: SQLAlchemy session, presumably from get_db_session
+    table_object: SQLAlchemy ORM table object, defined in the file above
+    constraints: key-value pairs to match against specific fields in the database
+                Note: Currently, only the query.ilike method is supported. This is intended to
+                eventually support the entire range of available filters.
+    '''
     query = session.query(table_object)
 
     for key, value in constraints.items():
@@ -69,6 +117,7 @@ def search(session, table_object, inclusive=True, **constraints):
 
 @contextlib.contextmanager
 def get_db_session():
+    '''Get a SQLAlchemy database session with a proper context object. '''
     session = _db_session_maker()
     try:
         yield session