Speed up publishing and "add new page"

Hi

Just so you know, I am very new (2 weeks) to wordpress. My site already has close to 1500 pages and should go up to at least 3000, excluding photo galleries and slideshows that still need to be created.

My wordpress admin area is becoming increasingly slower (up to 6 minutes to publish a new page) and sometimes does not respond at all, resulting in me rebooting my laptop to try and resolve the issue, to no avail.

I have installed W3 Total Cache, which helped to some extent, but only for a short while.

Any help would be much appreciated.