If you try to download an app from the Android Market from your Android phone and get stuck at “starting download” and the progress bar does not continue, the first and easiest thing to do is to cancel the download, shut down the phone, and restarting the phone, and then try the download again.
Android phone runs on Google Android operating system. Phones are like computers these days. So restarting the phone is like restarting the computer. Just like back in the old computer days, restarting them sometimes help clear things from memory and help solve some problems.
1) Restart the Phone
My Android phone was stuck at downloading and restarting my phone made it worked.
However, that may not be the fix for everyone or every situation. Apparently many people have encountered this problem as noted by the long Google Android market support thread. You may find some additional things to try in that thread.
2) Start GTalk
Second thing to try is to start GTalk on your phone. This is one of the things mentioned in Android Market Troubleshooting Download Issues. Sometimes GTalk won’t start either. It just comes up for a brief instant and disappears. This happened to me too, and restarting the phone fixed that issue too.
3) Try connecting via WiFi.
Another thing to try is to turn on WiFi and use a WiFi connection.