Are sitemaps and robots.txt important?

helly guys, thanks for this forum, big help.

i built a sitemap using xml-sitemap but it says that if i build the sitemap with the www, its different than the one without www- meaning: www(dot)puertogalera(dot)org is different from puertogalera(dot)org - Question: which is better, sitemap with the www or without the www

also i would like to know how to build a good robots.txt which would point to a sitemap that i regularly update and what to avoid in robots.txt

please help, my site went from number 4 to number 14 and its still sliding down.

robots.txt doesn't point an SE web crawler to a page to crawl. Infact it does the opposite; it tells a crawler what not to look at.

Re: www or !www
It's probably better practice to pick one, and mod-rewrite your server to handle requests at either, then use that which you selected. One is not better than the other, but using both subdomains (or lack there of) results in duplicate content (because they are seen as being different "sites").

You have to decide first what is the canonical version of the site. Most prefer the www version. So in this case, the URL's in the sitemap should be written in www version.

Choosing the canonical version is easy. If your pages are ranking for www version, then use www version. Google also choose what are your canonical versions. But to make work easy, make it standardized, if you say you are ranking for www version..Then.

You backlinks should also to www versions, so as .. internal links, your sitemap.

You can set your domain association in Google webmaster tools .

As a guide in what URLs are to be blocked in robots. Just spot all those URLs that you will not need Google to index. Block those URLs to save bandwidth.

It will make your site easy to crawl because Google will prioritize those important URLs you specify in your site and what is not allowed in robots.txt

Sitemap and robots.txt even how good it is, does not relate directly to ranking (although indirectly it relates). Instead focus more on developing relevant content and follow good optimization guidelines.

Then with relevant content, it will be easier to get inbound links with keywords in anchor text which really helps a lot in terms of Google ranking.

The bottom line... relevant, genuine content and keywords in anchor text.

So that is the reason why my ranking went down ... I changed my sitemap to !www instead of www.. google thought it must be a duplicate file and penalized my site... Thanks a lot... I changed it back to www... Will google return me to my original ranking...

thanks a lot for helping me out... thank you too perma

www, or not www If you don't use www you save 3 symbols, which can change the displayed URL in google (since google shows only 100 symbols in it's SERP urls).