The best way to start creating a queXML document is to download the queXML package and start editing the example questionnaire in the package. This will give you an overview of the structure of a queXML document. An XML editor will make this job easier.
An overview of queXML is available in this document: Beginners guide to queXML
The structure of queXML is available in this document (good for having up on the wall when creating queXML documents!) An overview of the structure of queXML (queXML Schema)
queXML and LimeSurvey
To quickly create queXML instruments, install the latest stable version of LimeSurvey. All versions after 1.70 have the ability to export a questionnaire designed in LimeSurvey to queXML. Therefore you can use LimeSurvey to create queXML files (which can be converted to well structured PDF files for use with queXF), and run your web based questionnaires.
Once you have created your instrument in LimeSurvey, export the structure to queXML, then convert it to a PDF using the ACSPRI queXML Tools.