The following links go to favorite free resources that focus on building your research skills.
FamilySearch Wiki – An online genealogy encyclopedia – great for learning the resources that available for locations throughout the world.
FamilySearch Learning Center – Presentations and videos on a broad range of topics.
Ancestry.com Family History Wiki – Another encyclopedia focused on genealogy research – includes copies of The Source: A Guidebook to American Genealogy and Red Book: American State, County and Town Sources.
Legacy Family Tree Webinars - "Genealogy education, where you are!" Online webinars on hundreds of topics. While unlocking the full array of features requires a paid subscription, all of their new webinars are FREE for the live presentation and for one week afterwards. A few remain free for much longer.