Do you get any errors?
if this is your first app, its probably to do with setup and enviroment. Whats your system spec?
I found running the install process - you have to make sure you follow the installation process in a good sequence. Eclipse, android platform. Java enviroment then ADT plugin.
the AVD Manager updater should have taken a long time to get everything you need when you run it.
If it failed - There is a little check box in the settings of the AVD manager that allows you to force download the HTTP -
But as long as you've got the lot, and your building a 2.1 file.
Also, the first time you run the emulator, it'll sit quiet for a worrying amount of time. Just make tea, watch TV - google kayden kross and it'll be fine.