In addition to using the Smarty template usage indicator option to answer the question which template do I modify?, this template map lists the templates used for specific features.
{NOTE()}This template map is based on the default Tiki installation. The templates used on your site may vary depending on your options and theme.{NOTE}

The primary Tiki template is: tiki.tpl

It includes the following:

header.tpl 
..header.tpl
....tiki-site_header.tpl 
......tiki-site_header_top.tpl 
......tiki-site_header_top_begin.tpl 
......tiki-secondary_sitemenu.tpl 
......tiki-site_header_options.tpl 
......tiki-site_header_login_popup.tpl 
......tiki-site_header_top_end.tpl
....tiki-top_bar.tpl 
......tiki-top_bar_begin.tpl 
......tiki-sitesearchbar.tpl 
........tiki-searchresults.tpl 
......tiki-sitemenu.tpl
......tiki-sitelocbar.tpl
......tiki-top_bar_end.tpl 
....tiki-top_bar_custom_code.tpl

modules/*.tpl 
..module.tpl 
....

modules/user_module.tpl
..module.tpl

modules/*.tpl
..module.tpl 
....

modules/user_module.tpl
..module.tpl

....tiki-bot_bar.tpl
......credits.tpl
....footer.tpl

Wiki Pages

tiki-show_page.tpl  
..freetag-list 
..tiki-wiki_topline.tpl 
..rating.tpl 
..wiki_authors.tpl 
..show_copyright.tpl 
..tiki-page_bar.tpl 
....comments_button.tpl 
....attachments.tpl 
....comments.tpl 
......tiki-edit_help.tpl 
......tiki-edit_help_plugins.tpl 
......antibot.tpl 
tiki-show_help.tpl 
..For each active plugin:
..tiki-plugin_help.tpl

Articles

Read article:

tiki-read_article.tpl
..freetag_list.tpl
..article_trailer.tpl
..show_copyright.tpl

View article:

tiki-view_articles.tpl

Forums

Forum List

tiki-forums.tpl

Forum View

tiki-view_forum.tpl
..tiki-edit_help.tpl
..tiki-edit_help_plugins.tpl
..antibot.tpl

Forum Thread

tiki-view_forum_thread.tpl
..comment.tpl
....comment-header.tpl
....comment-body.tpl
....comment-footer.tpl
..comments.tpl
....tiki-edit_help.tpl
....tiki-edit_help_plugins.tpl
....antibot.tpl

Blogs

View Blog

tiki-view_blog.tpl
..blog_wrapper.tpl
....blog_post_postbody_title.tpl
......freetag_list.tpl
....blog_post_author_info.tpl
....blog_post_postbody_content.tpl
......show_copyright.tpl
....blog_post_author_actions.tpl
....blog_post_actions.tpl
....blog_post_status.tpl
....blog_post_navigation.tpl

View Blog Post

tiki-view_blog_post.tpl
..blog_wrapper.tpl
....blog_post_postbody_title.tpl
......freetag_list.tpl
....blog_post_author_info.tpl
....blog_post_postbody_content.tpl
......show_copyright.tpl
....blog_post_author_actions.tpl
....blog_post_actions.tpl
....blog_post_status.tpl
....blog_post_navigation.tpl