Does anyone know even roughly how long it would take for google to take into account a new title or description i have put in place of the old one. I have to experiment with my title and description to make it more relevant and was wondering
Sad fact is, Google is taking longer and longer with this kind of thing. No one can really tell you. I've seen it take WEEKS
Each time you change a page title (or anything on the page), go to Fetch As Google in your Google Webmaster Tools and "Fetch" the page. That will almost certainly get Google to crawl that page very quickly. Now how long it will take before that affects that page's ranking ... that's another story. But "Fetch" will get you a quick crawl.