I'm trying to set up org-publishing for two sites, with the intention of
moving away from wordpress.

I have set it up using "taste" and "tgmeds" to delineate each site.

--8<---------------cut here---------------start------------->8---
(setq org-publish-project-alist
'(("taste"
:base-directory "~/.emacs.d/orgblog/taste/"
:publishing-directory "~/.emacs.d/blog/taste/"
:makeindex non-nil ; index generation
:section-numbers nil
:with-toc nil
:html-head "<link rel=\"stylesheet\"
           href=\"../other/mystyle.css\"
           type=\"text/css\"/>"
(define-key org-mode-map (kbd "C-c C-1a") 
   (lambda () 
      (interactive) 
      (org-publish "foo")))
))

'(("tgmeds"
:base-directory "~/.emacs.d/orgblog/tgmeds/"
:publishing-directory "~/.emacs.d/blog/tgmeds/"
:makeindex non-nil ; index generation
:section-numbers nil
:with-toc nil
:html-head "<link rel=\"stylesheet\"
           href=\"../other/mystyle.css\"
           type=\"text/css\"/>"
;(define-key org-mode-map (kbd "C-c C-1t") 
;   (lambda () 
;      (interactive) 
;      (org-publish "foo")))
)))
--8<---------------cut here---------------end--------------->8---

I'm able to write the postings and get them converted to html, but when
I try to use the export and publish functions it is failing. It then
shows this in "*Backtrace*"

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (error "No publishing function chosen")
  signal(error ("No publishing function chosen"))
  error("No publishing function chosen")
  org-publish-file("/home/boudiccas/.emacs.d/orgblog/taste/anewmv.org")
  org-publish-current-file(nil nil)
  org-export-dispatch(nil)
  #<subr call-interactively>(org-export-dispatch nil nil)
  ad-Advice-call-interactively(#<subr call-interactively> org-export-dispatch nil nil)
  apply(ad-Advice-call-interactively #<subr call-interactively> (org-export-dispatch nil nil))
  call-interactively(org-export-dispatch nil nil)
  command-execute(org-export-dispatch)
--8<---------------cut here---------------end--------------->8---

I am calling org-publish by "C-c C-e P p" which then shows this in
"*Messages*"

--8<---------------cut here---------------start------------->8---
Loading /home/boudiccas/.org-timestamps/taste.cache...done
org-publish-file: No publishing function chosen
--8<---------------cut here---------------end--------------->8---

How can I then publish my postings, and also generate the necessary
index.html file please?

Thanks
Sharon.
-- 
A taste of linux = http://www.sharons.org.uk
TGmeds = http://www.tgmeds.org.uk
Debian 8.0, fluxbox 1.3.7, emacs 24.5.50.3