Existing databases and archives
If you are interested in researching advice giving, there are a number of collections that are publicly accessible for further analysis. These include:

The Wellcome Trust (UK)
Within the Wellcome Library there are numerous pamphlets, magazines and self help books on physical and mental health, sex and relationships. Letters asking for help and advice sent to Marie Stopes, EF Griffith and Grantly Dick Read can be found here.

The British Library
An extensive, historical archive of newspapers, magazines and comics can be found in the Newsroom at St Pancras (London). Or you can see more updates from the British Newspaper Archive on Facebook.

The Kinsey Institute
The KI’s library hosts a range of  archived collections you can use for research and writing. These include the letters sent to Dr Kinsey, Leonore Tiefer’s correspondence from her years as an agony aunt at Playboy magazine plus newsletters and magazines from the mid 20th Century onwards.