One-to-many and many-to-many relation between nodes of different content types
The Relation module itself provides a block that can be used to create relations, you can create a simple relations by configuring relations and entity collector or can use the Rules module to create relations.

If your want to set up a relationship between entities than you may use the relation_add module: It provides a block that allows the user to add an appropriate relation from an entity page to any other appropriate entities, with a generic autocomplete for each endpoint, and relation fields. Tutorial for relation add module.

Tutorials for creating a relation type (administration toolbar &gt; Structure &gt; Relation types):
https://drupal.org/node/1276284
http://nodeone.se/en/creating-a-first-relation-type-the-entity-collector
http://nodeone.se/en/directional-relations-and-fields-on-relations

Few Tutorials that may be useful for you:
http://vimeo.com/28178686
http://nodeone.se/en/learn-the-relation-module
https://drupal.org/node/1276298
https://drupal.org/node/1276380