I recently upgraded my site from 1.39 to 1.51 (through a freelancer) and since then it has been nothing but problems. I need someone who can fix the problems below and check for any other issues. Since changing to 1.51 my google ranking has dropped, google is now only indexing my categories and not my products.
Make sure I have the most recent (and stable) USU.
Configure the settings for USU to match your needs / wants (URL Format, Redirects, etc).
Regenerate the sitemap to be accurate.
Open up Google Webmaster Tools and take care of any warnings, issues, or errors.
convert the db data and tables to UTF8 (currently special characters do not work eg: éüÇ
Fix any 301 redirects