Taxonomy view resulting content fields
By default the output at taxonomy/term/% (with % being the term ID) is a collection of teasers for nodes to which the term ID is assigned. 

You can alter the teaser display for each content type by going to Structure > Content types > [type] > Manage Display > Teaser. This is the simplest method, but note that this will alter the teaser display for the content type site-wide, not just on the taxonomy term results page. 

If you want to alter the overall display of the results and you don't want to alter the teaser output everywhere else, @ShawnCohen's answer is your best bet. Views provides some powerful options for customizing a result set, including Relationships (mentioned by @Screenack in the comments).