David Burch of Starpath is well known as a marine navigation and weather expert. In his latest book, Introduction to Electronic Chart Navigation (which can be ordered at the Starpath website), he explains the various types of electronic charts and how voyagers can make the most of them. It's a highly detailed book and an excellent sourcebook for navigators.
In a recent blog post on the Starpath site Burch details an interesting wrinkle in how various electronic chart programs implement the International Hydrographic Organization's S-52 electronic chart standard as it pertains to displaying minor lights. It's a concrete example of how complex the S-52 vector chart standard is and how it is sometimes interpreted slightly differently. You can read the full blog post here.