Need advice for indexing a multilingual website

[Qualbe-Marketing-Group]

We are in the process of creating a Spanish subdomain of our website. I want to know what needs to be done in regard to meta tags, sitemap.xml and robots.txt so that Google and Bing will index both website properly and not causing the web page on the English site to lost rank.

Our English site is www.mydomain.com with the Spanish site being es.mydomain.com

We are planning to put a button or link on both sites so that visitors can switch between both sites.

The two sites are similar but not all pages are mirror images.

[john4math]

First, make sure you set the geographic target in your Google Webmaster Tools if you have a specific geographic target.  If not, Google recommends you don't set a geographic target it just for language purposes (see here).  In that case, Google will figure out the language on its own (see here).

You have a few options for setting the language on the page, which is what Bing is looking for.  They have a nice write-up about it here.

Each subdomain can have its own sitemap and robots.txt, so set those up like you would normally.

[Qualbe-Marketing-Group]

Thank you, John. That is helpful.