This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
JAR files don't really have an icon. (Unless you're talking about whatever Windoze displays for you). It all depends on who's displaying the icon. Ask that program's documentation where to put the icon. This isn't addressed in the JAR specification I believe.