For me, an invaluable companion for learning openings has been <a href="http:&#x2F;&#x2F;www.eudesign.com&#x2F;chessops&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.eudesign.com&#x2F;chessops&#x2F;</a>. The design of the site is unchanged since ca. 1995, but it works well.