Google Sites

1. Contact Form

Can use JotForm for contact form that send you email from your web site
Ex: OEM contact page http://www.jotform.com/?formID=51298047806461

2. SEO - Search Engine Operator

You can use https://www.xml-sitemaps.com/ to build  site-map for you Google site. Once you build the site map, upload it to your web site using  "Attachment " under "Mange Your Site"

3. Google Web Master

• Go to "Crawl" -> "SiteMaps" to ubmit the site-map you uploaded.
• Then "Fetch as Google" and Submit.

4. Adding Sub Menu Tabs/Links

Go to "Edit Site Layout" -> "Edit Horizontal Navigation", And use Arrows to make sub menu/tabs