The best way to find what you need is by using the search box - the search engine applies to the whole site so should give you the result you need.
The main navigation tool on the site is the boxes at the top of pages which click through to different sections. For the Editorial Guidelines these are coloured green, for the Online Services Guidelines these are coloured peach, for Guidance these are coloured pale green, and for Referrals these are coloured red. Each section also is differentiated by a logo. A book for Editorial Guidelines, a computer for Online Services guidelines, an information symbol for Guidance and an exclamation mark for Mandatory referrals.
The Editorial Guidelines and Online Services Guidelines also have their own A-Z indexes.
On the right hand side of the page there is a blue box called "Content producers must also read". This includes links to other relevant sections of the Guidelines.
If you want to interact with a human being, look at the "Contact Editorial Policy" page where there is an email and phone number.