It includes step-by-step examples and lots of screen shots.
You will learn how to use the GRO Index to locate missing maiden names, find missing children (born and died between census years), find death ages and birth years of those born before 1837.
The guide is a PDF which can be downloaded by clicking HERE.
I hope this guide helps you use the GRO Index to its full advantage.
Thanks again for your interest and use of the Online Genealogical Index. Combined with the GRO Index, FreeBMD and the UK census (1841-1911 free at FamilySearch.org), you will find further generations of your ancestors quickly.
Best regards from a fellow genealogist!