My Site Has Vanished. Help!!

[petem]

Hi, can anyone advise me on this problem.
I have a small site designated to my local plastering business.
For the last 18 months or so it has ranked in the top three of all the major search engines including Google when using the search phrase;
plastering or plasterers Reading Berks
plastering berks
plasterers berks etc.
(It usually has three or four pages listed on the first search page).

Yesterday I made a manual submission as I usually do every six to eight weeks. (I'd been told some time ago on another forum that it was recommended to do so). However, when I did my daily quick check later I've discovered that my site is nowhere in the first ten pages no matter which search term I use.

The other main search engines have not been affected and still display the site in the top three regularly. Could anyone enlighten me as to what is likely to have caused the sudden 'dropping' of my site?

I have added my blog link in the last couple of weeks, surely this wouldn't affect it?

Thankful in anticipation, Pete