You can do lots of things with the Query Analyzer.
John West has a nice introduction here.
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