With these two posts you will be able to get your base joomla site setup quickly so that the real work can begin which is adding the content can developing the site.
Here are the standard Extensions we use to start out most Joomla sites:
Akeeba https://www.akeebabackup.com/
- Admin Tools -- Great for basic admin and Joomla Update Tasks
- Backup -- Used to backup sites and move them from server to server
NoNumber Extensions http://www.nonumber.nl/
- modules anywhere -- Allows you to display modules inside of articles and categories
- cache cleaner -- adds a cache clean button to the admin interface
- advance module manager -- gives you better control of what pages modules display on
JCE http://www.joomlacontenteditor.net/
- JCE Caption
- JCE iFrame
- JCE File Manager
- JCE Image Manager
RSS Feeds http://foobla.com/joomla/obrss
- obRSS -- commercial extenstion to create / edit / manage rss feeds from your site
- obRSS Merge -- merge all of your rss feeds into one feed
- k2 RSS -- create an rss feed from your k2 items.
Sitemap http://joomla.vargas.co.cr/en/downloads/components/xmap
- xMap -- great for creating sitemaps for users and to be submitted to Google
SEF URLS
Cache & Performance
- JotCache -- http://www.jotcomponents.net/web-programming/jotcache/download/actual-versions
- ScriptMerge -- http://www.yireo.com/software/joomla-extensions/scriptmerge
- CDN for Joomla -- http://www.nonumber.nl/extensions/cdnforjoomla/
Misc
- HeaderTags - Changes the first h2 to h1 (if no h1 exists) http://extensions.joomla.org/extensions/site-management/seo-a-metadata/meta-data/14835
Standard Joomla config changes
- Article Options - All to not show except title
- SmartSearch Configuration