query syntax in sitecore rocks' query analyzer

Other than that, using the Help keyword can give you some pointers. If you type help select you get some detailed help on the select keyword - including the EBNF syntax.

You can also use the scripting commands from the Sitecore Explorer: Tools | Script | Select.

Here are an example:

Select Title and Text fields from all items under /sitecore/content that uses the Sample Item template.

select @title, @text from /sitecore/content//*[@@templatekey = 'sample item']

Notice the @@ before the system attribute templatekey.

Other than that you should be familiar with identifier escaping. Since Sitecore field names may contain spaces, you have to enclose them in ##.

This selects the field Long Text from home:

select @#Long Text# from /sitecore/content/Home