If you are interested in doing some programming, download the Google Web APIs Developer’s Kit (http://www.google.com/apis/download.html). While not strictly necessary to any Google API programming you might do, the kit contains much that is useful:
A cross-platform WSDL file (see below)
A Java wrapper library abstracting away some of the SOAP plumbing
A sample .NET application
Documentation, including JavaDoc and SOAP XML samples
Simply click the download link, unzip the file, and take a look at
the README.txt
file to get underway.