There are tons of website around to guide you on linux, for Ubuntu related articles, please visit http://www.digg.com as this social content website will usually have some interesting Ubuntu related website on the front page.
This link here is a tutorial on how to create a linux Desktop App, I hope this is what you are looking for http://www.clivecooper.co.uk/tutorial/index.html
To get yourself familiar with the commands used in Linux, please check out this page http://blog.lxpages.com/ultimate_linux.html
[Intro]Linux & Open Source Software, Readme 1st