Google i18n team developed a tool to create detailed report of fonts. The tool named fontreport, produces a multi page PDF with Unicode coverage of the font, what glyphs are in it, what Open Type features it supports, available ligatures, and glyph substitutions. Optionally the tool can also create plain text reports. The PDF is generated using TeX.
I found it very useful to create report for a dozen of fonts I maintain with Swathantha Malayalam Computing community. Sharing the reports it created: