If you just started programming your first 2D game using AndEngine, here are some tips for you. These tips are more about "Game Programing" in general, then about AndEngine, but I think you should know it before get started programming your own game.
What you should know abot textures before get started programming your first game.
Script for creating Android icons for different screen resolutions at once. Icons can be saved using standard Android icons naming conventions and saved in appropriate folders.
Source code with examples how to use relative layout to create nice buttons with text and images in Android
Tutorial about connecting to the web pages on the Internet from Android application, using both POST and GET web requests.