Java Developer's Guide v1.1: http://www.forum.nokia.com/info/sw.nokia.com/id/aca87303-e7ef-4a5a-9274-7e0973d52e94/Java_Developers_Guide_v1_1_en.pdf.html
This document can provide with a great start for any developer looking to exploit their Java skills in the mobile arena. The document provides an overview of the Series 40 platform and the Java APIs supported by Nokia also.
Take a look at this updated developer's guide. It provides an overview to the platforms, development tools and distribution mechanisms for apps created using Java technology for Nokia devices. It also emphasizes on the latest Nokia‚Äôs Touch and Type UI and how Java applications may take advantage of its features.